Indefinite
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C1 adjective /ɪnˈdefɪnət/

Indefinite

indefinido
Meaning
not clearly defined; uncertain; vague; unlimited in time
Example
The meeting has been postponed for an indefinite period.
La reunión se ha pospuesto por un período indefinido.
B2 adverb /ɪmˈpɒlɪtli/

impolitely

de manera grosera
Meaning
in a rude or discourteous manner; without showing respect or proper manners
Example
He spoke impolitely to the waiter despite the polite service.
Habló de manera grosera con el camarero a pesar del buen servicio.
C1 noun /ˈɪtʃ.i.nəs/

itchiness

picazón
Meaning
The quality or condition of feeling an irritating sensation on the skin that causes a desire to scratch.
Example
Eye itchiness often leads to rubbing.
La picazón en los ojos a menudo conduce a frotarse.
C1 noun /ˌɪnækˈtɪvɪti/

inactivity

inactividad
Meaning
the state of not being active physically or mentally; lack of action
Example
Prolonged inactivity can negatively affect both physical and mental health.
La inactividad prolongada puede afectar negativamente la salud física y mental.
B2 noun /ˌɪnsɪˈkjʊərɪti/

insecurity

inseguridad
Meaning
lack of confidence or assurance; a state of uncertainty or vulnerability
Example
Her insecurity made her doubt her abilities despite her experience.
Su inseguridad la hizo dudar de sus habilidades.
C1 noun /ˌɪndɪɡˈneɪʃən/

indignation

indignación
Meaning
Strong displeasure or anger caused by something unjust, offensive, or insulting.
Example
Public indignation grew after the unfair verdict.
La indignación pública creció después del veredicto injusto.
C1 noun /ˈɪn.fən.tri/

Infantry

infantería
Meaning
soldiers marching or fighting on foot; foot soldiers collectively
Example
The infantry advanced across the battlefield on foot.
La infantería avanzó a través del campo de batalla a pie.
B2 noun /ɪnˈveɪʒən/

invasion

invasión
Meaning
An instance of invading a country, region, or personal space with armed force or unwelcome presence.
Example
The army prepared for the possibility of an invasion.
El ejército se preparó para la posibilidad de una invasión.
C1 noun /ˌɪməˈrælɪti/

immorality

inmoralidad
Meaning
the quality of being immoral; behavior that violates accepted moral standards
Example
The community condemned the immorality of the corrupt officials.
La comunidad condenó la inmoralidad de los funcionarios corruptos.
C1 adjective /ɪˈrɛvəkəbl/

irrevocable

irreversible
Meaning
Not able to be revoked, changed, or undone.
Example
She made an irrevocable decision to leave the company.
Ella tomó una decisión irreversible de dejar la empresa.
B2 noun /ɪnˈdʒɛkʃən/

injection

inyección
Meaning
the act of introducing a substance into the body through a needle
Example
The nurse gave me an injection to prevent the infection.
La enfermera me dio una inyección para prevenir la infección.
C2 noun /ɪnˈtɛnʃən/

intension

contenido interno
Meaning
The internal content of a concept; the set of attributes implied by a word or phrase.
Example
The intension of the word 'dog' includes being a mammal and domesticated.
La intensión de la palabra 'perro' incluye ser un mamífero y ser domesticado.
B2 adjective /ɪˈmens/

Immense

inmenso; colosal; enorme
Meaning
extremely large or great; huge
Example
The immense mountain range stretched across the horizon.
La inmensa cadena montañosa se extendía a lo largo del horizonte.
C1 noun /ɪmˈprɪzənmənt/

imprisonment

encarcelamiento
Meaning
the act of putting someone in prison; the state of being confined as punishment
Example
He faced imprisonment for violating the court order.
Se enfrentó al encarcelamiento por violar la orden judicial.
B2 verb /ˈɪr.ɪ.teɪt/

irritate

irritar
Meaning
To make someone annoyed or angry; to cause discomfort or inflammation.
Example
Rubbing your eyes can irritate them.
Frotarse los ojos puede irritarlos.
C1 adjective, noun /ɪnˈdɪkətɪv/

indicative

indicativo
Meaning
Serving as a sign or expression of something; in grammar, a mood used to make factual statements.
Example
His tone was indicative of his frustration.
Su tono era indicativo de su frustración.
B2 noun /ɪnˈsaɪdə/

insider

insider
Meaning
a person within a group or organization who has access to confidential information
Example
He was an insider who knew all the company's secrets.
Él era un insider que conocía todos los secretos de la empresa.
C1 noun /ɪnˈsɜːrdʒəns/

insurgence

insurgencia
Meaning
An act of rebellion or uprising against authority.
Example
The government struggled to contain the growing insurgence.
El gobierno luchó por contener la creciente insurgencia.
C2 verb /ˈɪmprɛɡneɪt/

impregnate

embarazar / impregnar
Meaning
To make pregnant; to fill or saturate with something.
Example
The scientist used a method to impregnate the material with resin.
El científico utilizó un método para impregnar el material con resina.
B2 adjective ˈaɪsəˌleɪtɪd

isolated

aislado
Meaning
Alone or separated from others; having little or no contact with other people.
Example
Technological advancements often leave people isolated.
Los avances tecnológicos a menudo dejan a las personas aisladas.
B2 noun ɪnˌdʌstrɪəlaɪˈzeɪʃən

industrialization

industrialización
Meaning
The development of industries in a country or region on a wide scale.
Example
Industrialization changed the global economy dramatically.
La industrialización cambió drásticamente la economía global.
C1 adjective /ˌɪn.dɪˈspen.sə.bəl/

indispensable

indispensable
Meaning
Absolutely necessary, essential
Example
Water is indispensable for human survival.
El agua es indispensable para la supervivencia humana.
C2 noun /ɪˌluːmɪˈnɑːti/

illuminati

iluminati
Meaning
a group of people claiming to have special enlightenment or secret knowledge, often linked to conspiracies
Example
Many conspiracy theories involve the Illuminati as a secret world-controlling group.
Muchas teorías de conspiración involucran a los Illuminati como un grupo secreto que controla el mundo.
B2 adjective /ˈaɪ.dəl/

Idle

perezoso; inactivo; no trabajando
Meaning
lazy; inactive; not working or being used
Example
The factory workers were idle during the strike.
Los trabajadores de la fábrica estaban inactivos durante la huelga.
C1 adjective /ɪˈnuːmərəbəl/

Innumerable

innumerable; incontable; infinito
Meaning
too many to be counted; countless; infinite in number
Example
There are innumerable stars in the night sky that we cannot see with our naked eyes.
Hay innumerables estrellas en el cielo nocturno que no podemos ver con nuestros ojos desnudos.
C1 verb /ɪnˈfɛst/

infest

infestar
Meaning
to overrun in large numbers, especially so as to cause damage or discomfort
Example
The old house was infested with rats.
La vieja casa estaba infestada de ratas.
B2 noun, verb /ɪntʃ/

inch

pulgada / moverse lentamente
Meaning
A unit of length equal to 2.54 centimeters; or to move slowly and carefully in small amounts.
Example
She inched closer to the edge of the stage.
Ella se acercó lentamente al borde del escenario.
B2 adjective ɪnˈdɪdʒɪnəs

indigenous

indígena
Meaning
Originating or occurring naturally in a particular place; native.
Example
Indigenous plants are well adapted to the local environment.
Las plantas indígenas están bien adaptadas al entorno local.
C2 adverb /ˌɪnəzˈmʌtʃ/

inasmuch

en la medida en que
Meaning
To the extent that; considering that.
Example
Inasmuch as you are their teacher, you should guide them carefully.
En la medida en que eres su maestro, deberías guiarlos cuidadosamente.
C2 noun /ˌɪntərpəˈzɪʃən/

interposition

intervención
Meaning
The act of intervening or coming between two things, often to influence or prevent an outcome.
Example
The manager’s interposition prevented a heated argument from escalating.
La intervención del gerente evitó que una discusión acalorada se intensificara.
A2 noun /ˈɪndʒəri/

injury

lesión
Meaning
Harm or damage to a person’s body caused by an accident or attack.
Example
He suffered a serious injury during the football match.
Sufrió una lesión grave durante el partido de fútbol.
C1 verb /ˈɪtəreɪt/

iterate

iterar
Meaning
To repeat a process or statement, often to improve or refine.
Example
The software team will iterate the design until it meets user needs.
El equipo de software iterará el diseño hasta que cumpla con las necesidades del usuario.
C2 adjective /ˌaɪsəʊˈθɜːrməl/

isothermal

isotérmico
Meaning
Having or maintaining equal or constant temperature.
Example
The experiment was conducted under isothermal conditions.
El experimento se realizó bajo condiciones isotérmicas.
C2 verb /ˌɪntərˈmɪt/

intermit

interrumpir
Meaning
To suspend or stop for a time; to pause intermittently.
Example
The rain would intermit and then start again.
La lluvia se interrumpiría y luego comenzaría de nuevo.
B2 adjective /ˈɪnˌsaɪtfəl/

insightful

perspicaz
Meaning
Showing deep understanding or perceptiveness.
Example
The professor gave an insightful lecture on global economics.
El profesor dio una conferencia perspicaz sobre la economía global.
C1 adjective /ˈɪntrɪkət/

intricate

intrincado
Meaning
very detailed, complex, and difficult to understand
Example
The artist created an intricate pattern on the wall.
El artista creó un patrón intrincado en la pared.
C1 adjective /ˈɪnfəməs/

infamous

infame
Meaning
well known for some bad quality or deed
Example
The dictator was infamous for his cruelty.
El dictador era infame por su crueldad.
C1 verb /ɪnˈfjʊərieɪt/

infuriate

enfurecer
Meaning
To make someone extremely angry.
Example
His careless remarks infuriated the entire team.
Sus comentarios descuidados enfurecieron a todo el equipo.
C1 adjective /ɪnˈtændʒəbl/

intangible

intangible
Meaning
Unable to be touched or grasped; not having a physical presence.
Example
Trust is an intangible quality in relationships.
La confianza es una cualidad intangible en las relaciones.
B2 adjective ˈɪn.tɪ.ɡrəl

integral

integral
Meaning
Necessary to make a complete whole; essential or fundamental.
Example
Exercise is an integral part of a healthy lifestyle.
El ejercicio es una parte integral de un estilo de vida saludable.
C2 noun /ˌɪn.ɪˈbraɪ.ə.ti/

inebriety

embriaguez
Meaning
the state of being drunk or intoxicated
Example
His frequent inebriety led to the loss of his job.
Su frecuente embriaguez le llevó a perder su trabajo.
C2 noun /ɪnˈɛrənsi/

inerrancy

inerrancia
Meaning
the belief or quality of being free from error; absolute correctness
Example
Some religious groups strongly affirm the inerrancy of their sacred texts.
Algunos grupos religiosos afirman fuertemente la inerrancia de sus textos sagrados.
C1 adjective /ˌɪndɪˈfɛnsəbl̩/

indefensible

indefendible
Meaning
not able to be protected or justified
Example
The minister’s remarks were considered indefensible by the public.
Los comentarios del ministro fueron considerados indefendibles por el público.
C2 verb /aɪˈdɒləˌtraɪz/

idolatrize

idolatrar
Meaning
To worship idols; to regard with excessive devotion or admiration.
Example
They began to idolatrize the statue as a deity.
Comenzaron a idolatrar la estatua como una deidad.
C1 noun ɪnˈflɛk.ʃən

inflection

inflexión
Meaning
The change in pitch or tone of voice when speaking for emphasis.
Example
His inflection kept the audience engaged.
Su inflexión mantuvo al público comprometido.
B1 adjective /ɪnˈtɜːrnəl/

internal

interno
Meaning
situated inside; relating to the inside or inner part of something
Example
The company is conducting an internal audit this month.
La empresa está realizando una auditoría interna este mes.
A2 noun /ˈaɪ.lənd/

Island

isla
Meaning
a piece of land completely surrounded by water
Example
We visited a beautiful island during our vacation.
Visitamos una hermosa isla durante nuestras vacaciones.
B2 adjective /ɪnˈtɒlərənt/

intolerant

intolerante
Meaning
unwilling to accept or respect beliefs or behavior different from one's own
Example
He is intolerant of any opinion that differs from his own.
Él no tolera ninguna opinión que difiera de la suya.
C2 adjective ɪnˈfiː.zə.bəl

infeasible

invable
Meaning
Not possible to do easily or conveniently; impracticable.
Example
Restoring the forest may become infeasible if destruction continues.
Restaurar el bosque puede volverse inviable si la destrucción continúa.
B1 verb /ɪnˈtend/

intend

intentar
Meaning
to plan or have in mind as a purpose; to mean
Example
I intend to finish this project by tomorrow.
Tengo la intención de terminar este proyecto para mañana.
A2 noun /ˈɪn.sekt/

Insect

insecto
Meaning
a small invertebrate animal with six legs and usually one or two pairs of wings
Example
The butterfly is a beautiful insect that flies from flower to flower.
La mariposa es un hermoso insecto que vuela de flor en flor.
B2 adjective /ɪnˈtɛnsɪv/

intensive

intenso
Meaning
Involving a lot of effort, energy, or concentration in a short period of time.
Example
She attended an intensive English course before moving abroad.
Ella asistió a un curso intensivo de inglés antes de mudarse al extranjero.
C1 noun /ɪnˈdaɪtmənt/

indictment

acusación formal
Meaning
a formal charge or accusation of a serious crime
Example
The indictment accused the company of multiple violations.
La acusación formal acusó a la empresa de múltiples violaciones.
C1 noun /ˌɪnkjʊˈbeɪʃən/

incubation

el proceso de mantener huevos, células u organismos en las condiciones adecuadas para su desarrollo
Meaning
the process of keeping eggs, cells, or organisms in the right conditions for development
Example
The incubation of the eggs lasted for three weeks.
La incubación de los huevos duró tres semanas.
B2 verb /ɪnˈdʌldʒ/

indulge

entregarse
Meaning
to allow oneself to enjoy something enjoyable, often excessively
Example
He indulged in a piece of chocolate cake after dinner.
Él se entregó a un trozo de pastel de chocolate después de la cena.
C1 adverb /ɪnˈvɜːrs.li/

Inversely

inversamente; en sentido opuesto
Meaning
in a way that is opposite or contrary; in reverse order or manner
Example
The price of goods is inversely related to their availability in the market.
El precio de los productos está inversamente relacionado con su disponibilidad en el mercado.
C1 adjective /ˌɪndɪˈvɪzəbl/

indivisible

indivisible
Meaning
Not able to be divided or separated.
Example
The country's unity was indivisible despite differences.
La unidad del país era indivisible a pesar de las diferencias.
B2 noun ɪnˈfleɪʃən

inflation

inflación
Meaning
A general increase in prices and fall in the purchasing value of money.
Example
Inflation erodes the purchasing power of consumers.
La inflación erosiona el poder adquisitivo de los consumidores.
B2 noun /ˈɪn.vɔɪs/

Invoice

factura
Meaning
a list of goods sent or services provided, with a statement of the sum due for these
Example
The company sent an invoice for the office supplies delivered last week.
La empresa envió una factura por los suministros de oficina entregados la semana pasada.
B2 adjective /ˈɪmpæktfʊl/

impactful

impactante
Meaning
Having a major impact or effect; powerful and forceful.
Example
Her impactful speech moved the audience to take action.
Su discurso impactante movió al público a tomar acción.
C1 adjective /ˈɪndɪɡoʊ bluː/

Indigo-blue

azul índigo
Meaning
a deep blue color with a purplish tinge
Example
The indigo-blue sky looked magnificent at twilight.
El cielo azul índigo se veía magnífico al atardecer.
C1 noun /ɪmˌpɒsəˈbɪlɪti/

impossibility

imposibilidad
Meaning
the state or fact of being impossible; something that cannot be done or achieved
Example
Finishing the project in one day was an impossibility.
Terminar el proyecto en un día fue una imposibilidad.
C1 noun /ˌɪn.dɪˈsɪʒ.ən/

Indecision

indecisión; duda; vacilación
Meaning
the inability to make decisions quickly; uncertainty about what to do
Example
Her indecision about which job offer to accept caused her to miss both opportunities.
Su indecisión sobre qué oferta de trabajo aceptar la llevó a perder ambas oportunidades.
C1 noun /ˌɪnˈdɪsəplɪn/

indiscipline

indisciplina
Meaning
lack of discipline or self-control; failure to obey rules or maintain order
Example
Indiscipline among the students disrupted the learning environment.
La indisciplina entre los estudiantes interrumpió el ambiente de aprendizaje.
B2 noun /ˌɪm.ɪˈteɪ.ʃən/

Imitation

imitación; copia; réplica
Meaning
the action of using someone or something as a model; a copy of something original
Example
His imitation of the famous actor was so good that everyone burst into laughter.
su imitación del famoso actor fue tan buena que todos estallaron en risa.
C1 adjective /ɪnˈvɛntɪv/

inventive

inventivo
Meaning
Having the ability to create or design new things or to think originally.
Example
The inventor was known for his inventive solutions to everyday problems.
El inventor era conocido por sus soluciones inventivas para los problemas cotidianos.
C2 adjective /ɪnˈɛk.wɪ.tə.bəl/

inequitable

inequitativo
Meaning
Not fair or just; lacking in fairness or equality.
Example
The distribution of resources was inequitable among the workers.
La distribución de recursos fue inequitativa entre los trabajadores.
B2 verb ˈɪmplɪment

implement

implementar
Meaning
To put a decision or plan into effect; to execute or apply.
Example
Implementing educational policies is essential for progress.
Es esencial implementar políticas educativas para el progreso.
C1 noun ˌɪntədɪˈpɛndənsi

interdependency

interdependencia
Meaning
The dependence of two or more people or things on each other.
Example
The interdependency of the countries led to greater cooperation.
La interdependencia de los países llevó a una mayor cooperación.
B2 noun /ˈaɪ.dəl/

Idol

ídolo; persona admirada
Meaning
an image or representation of a god used as an object of worship; a person who is greatly admired
Example
The singer became a teenage idol after her hit song topped the charts worldwide.
La cantante se convirtió en un ídolo adolescente después de que su canción de éxito llegara a la cima de las listas de éxitos mundiales.
C1 adjective /ɪnˈtɜːrmənəbl/

interminable

interminable
Meaning
Seemingly endless; having no apparent end.
Example
The meeting felt interminable and exhausting.
La reunión parecía interminable y agotadora.
C2 verb /ɪˈmjʊər/

immure

encerrar
Meaning
to confine or enclose someone against their will
Example
The prisoner was immured in a dark cell.
El prisionero fue encerrado en una celda oscura.
B1 adjective /ˈɪnəsənt/

Innocent

inocente; puro; inocuo
Meaning
free from guilt or sin; pure; harmless; naive
Example
The innocent child had no idea that her parents were planning a surprise party.
La niña inocente no tenía idea de que sus padres estaban planeando una fiesta sorpresa.
C2 noun /ˌɪnsəˈrɛkʃən/

insurrection

insurrección
Meaning
A violent uprising against an authority or government.
Example
The army was called in to suppress the insurrection.
El ejército fue llamado para sofocar la insurrección.
C1 adjective /ɪnˈvɪnsəbl/

invincible

invencible
Meaning
too powerful to be defeated or overcome
Example
The team seemed invincible after winning ten matches in a row.
El equipo parecía invencible después de ganar diez partidos consecutivos.
C1 adjective /ɪˈrɛpərəbəl/

Irreparable

irreparable
Meaning
impossible to repair or fix; permanent damage that cannot be undone
Example
The accident caused irreparable damage to his spine.
El accidente causó daños irreparables en su columna vertebral.
B2 noun /ɪˈluː.ʒən/

Illusion

ilusión
Meaning
a thing that is or is likely to be wrongly perceived or interpreted; a false idea or belief
Example
The magician created a spectacular illusion that made the elephant appear to vanish.
El mago creó una espectacular ilusión que hizo que el elefante pareciera desvanecerse.
C1 adjective /ɪnˈɔːdəbl/

inaudible

ininteligible
Meaning
Unable to be heard.
Example
Her voice was almost inaudible over the noise.
Su voz era casi ininteligible sobre el ruido.
C1 adjective /ɪmˈpæsəbəl/

impassable

intransitable
Meaning
Impossible to travel along or over.
Example
The road became impassable after the heavy snowfall.
La carretera se volvió intransitable después de la fuerte nevada.
C1 adjective /ɪnˈses.ənt/

incessant

incesante
Meaning
Continuing without pause or interruption; constant.
Example
The incessant noise from the construction site made it hard to concentrate.
El ruido incesante del sitio de construcción dificultaba concentrarse.
C1 noun /ˌɪntərˈdʒɛkʃən/

interjection

interjección
Meaning
a word or phrase used to express sudden emotion or reaction, often standing alone
Example
Words like 'wow' and 'ouch' are common interjections in English.
Palabras como 'wow' y 'ouch' son interjecciones comunes en inglés.
B2 adjective /ɪnˈtɛns/

intense

intenso
Meaning
Of extreme force, degree, or strength.
Example
She felt intense pain after the accident.
Ella sintió un dolor intenso después del accidente.
C2 verb /aɪˈtɪnəˌreɪt/

itinerate

itinerar
Meaning
To travel from place to place, usually for the purpose of work or preaching.
Example
The missionary itinerated throughout the region to spread the message.
El misionero viajó por toda la región para difundir el mensaje.
B2 verb /ˈɪntɪɡreɪt/

integrate

integrar
Meaning
To combine or bring together into a unified whole.
Example
The new system integrates data from multiple sources.
El nuevo sistema integra datos de múltiples fuentes.
C2 verb /ˈɪntərˌdɪkt/

interdict

prohibir
Meaning
to prohibit or forbid something by authoritative order, often by law or decree
Example
The court moved to interdict the sale of the illegal goods.
El tribunal se movió para prohibir la venta de los bienes ilegales.
C2 noun /ˈɪsməs/ or /ˈɪsθməs/

isthmus

istmo
Meaning
A narrow strip of land connecting two larger land areas, often with water on either side.
Example
The Panama Canal cuts through the Isthmus of Panama.
El Canal de Panamá corta a través del Istmo de Panamá.
B1 noun /ˌɪntərˈækʃən/

interaction

interacción mutua
Meaning
The process of people or things acting upon or influencing each other.
Example
The teacher encouraged more interaction between students.
El maestro alentó más interacción entre los estudiantes.
C1 adjective /ɪˈmuː.və.bəl/

immovable

inmóvil
Meaning
Not able to be moved; fixed in position.
Example
Immovable barriers prevent change.
Las barreras inmóviles impiden el cambio.
B2 noun /ɪnˈtɪəriər/

interior

interior
Meaning
the inside part of something; inner area of a place or object
Example
The interior of the hotel was beautifully decorated.
El interior del hotel estaba bellamente decorado.
C1 adjective /ˌɪn.səbˈstæn.ʃəl/

insubstantial

insustancial
Meaning
Lacking strength, substance, or solidity.
Example
The evidence provided was insubstantial and unconvincing.
La evidencia proporcionada fue insustancial y poco convincente.
B1 noun ˌɪnspɪˈreɪʃən

inspiration

inspiración
Meaning
The process of being mentally stimulated to do or feel something, especially to do something creative.
Example
His journey to success became an inspiration for many.
Su viaje al éxito se convirtió en una inspiración para muchos.
B2 noun /aɪˈdiː/

id

identificación
Meaning
identification; a document or number used to prove who someone is
Example
Please show your ID at the entrance.
Por favor, muestre su identificación en la entrada.
B2 noun /ɪmˈpeɪʃəns/

impatience

impaciencia
Meaning
The state of being quickly irritated or unable to wait calmly.
Example
His impatience grew as the meeting dragged on.
Su impaciencia creció a medida que la reunión se alargaba.
C2 adjective /ɪnˈvʌlnərəbl/

invulnerable

invulnerable
Meaning
Impossible to harm, damage, or defeat.
Example
The fortress was thought to be invulnerable to attack.
Se pensaba que la fortaleza era invulnerable al ataque.
C1 noun ɪnˈsɒl.vən.si

insolvency

insolvencia
Meaning
The state of being unable to pay debts owed; bankruptcy.
Example
The company declared insolvency after years of losses.
La empresa declaró la insolvencia después de años de pérdidas.
B2 noun ˌɪn.fləˈmeɪ.ʃən

inflammation

inflamación
Meaning
A localized physical condition in which part of the body becomes reddened, swollen, hot, and often painful.
Example
Chronic inflammation can lead to severe diseases.
La inflamación crónica puede causar enfermedades graves.
B2 noun ɪnˈsɛntɪvz

incentives

incentivos
Meaning
Things that motivate or encourage one to do something.
Example
Tax incentives are used to encourage investment in renewable energy.
Se utilizan incentivos fiscales para fomentar la inversión en energía renovable.
C1 adjective /ˌɪntərˈtʃeɪndʒəbl/

interchangeable

intercambiable
Meaning
able to be exchanged with each other without difference or loss of function
Example
These machine parts are interchangeable, so they can be replaced easily.
Estas piezas de la máquina son intercambiables, por lo que se pueden reemplazar fácilmente.
C2 noun /ɪnˈtɜːrstɪs/

interstice

hendidura
Meaning
a small space that lies between things
Example
Light filtered through the narrow interstices of the wall.
La luz se filtró a través de las estrechas hendiduras de la pared.
C1 noun /ˌɪnfɪˈdɛləti/

infidelity

infidelidad
Meaning
the act of being unfaithful to a spouse or partner
Example
Their marriage ended due to his infidelity.
Su matrimonio terminó debido a su infidelidad.
C1 adjective /ɪˈnɔːrdənət/

inordinate

excesivo
Meaning
Excessive or unusually large in degree.
Example
She spent an inordinate amount of time on her phone.
Ella pasó un tiempo excesivo en su teléfono.
C2 verb /ˌɪntərˈsiːd/

intercede

interceder
Meaning
to act or plead on behalf of someone in difficulty or trouble; to intervene between parties to help resolve a dispute
Example
She interceded with the teacher to give her brother another chance.
Ella intercedió con el maestro para darle otra oportunidad a su hermano.
C1 verb /ɪnˈfjuːz/

infuse

infundir
Meaning
to fill or spread through something; to instill a quality, idea, or feeling
Example
The teacher tried to infuse her students with a love for reading.
La profesora trató de infundir a sus estudiantes con un amor por la lectura.
C1 adjective /ɪˈrɛvərənt/

irreverent

irreverente
Meaning
showing a lack of respect for people or things that are usually respected
Example
The comedian’s irreverent jokes offended some of the audience.
Los chistes irreverentes del comediante ofendieron a algunos de la audiencia.
C1 adjective /ɪˈmeʒərəbəl/

Immeasurable

inconmensurable
Meaning
too large or extensive to measure; boundless
Example
The immeasurable love of a mother knows no bounds.
El amor inconmensurable de una madre no tiene límites.
C2 noun /ˈaɪ.ərn.wʊd/

Ironwood

madera de hierro
Meaning
a hard, dense wood from various trees; also the tree itself that produces small flowers
Example
The ironwood tree blooms with tiny white flowers.
El árbol de madera de hierro florece con pequeñas flores blancas.
B2 noun /ɪnˈvɒlvmənt/

involvement

participación
Meaning
the act of taking part in something
Example
His involvement in the project was crucial.
Su participación en el proyecto fue crucial.
C1 noun /ˈɪŋklɪŋ/

inkling

presentimiento
Meaning
A slight idea, hint, or suspicion about something.
Example
She had an inkling that he was planning a surprise.
Ella tenía una ligera sospecha de que él estaba planeando una sorpresa.
C2 adjective /ˌɪrɪˈfrændʒɪbəl/

irrefrangible

irrefrenable
Meaning
Not to be broken, violated, or infringed
Example
The constitution guarantees certain irrefrangible rights to every citizen.
La constitución garantiza ciertos derechos irrefrenables a cada ciudadano.
C1 adjective /ˌɪn.ɪˈfɛk.tʃu.əl/

ineffectual

ineficaz
Meaning
Not producing any or the desired effect; lacking the ability or qualities to achieve a purpose.
Example
The manager’s ineffectual leadership caused the team to lose motivation.
El liderazgo ineficaz del gerente hizo que el equipo perdiera la motivación.
B2 verb aɪˈdɛntɪfaɪd

identified

identificado
Meaning
To recognize or establish who or what someone or something is.
Example
The root causes of the issue need to be identified.
Las causas raíz del problema deben ser identificadas.
C1 verb /ɪˈnɔːɡjʊreɪt/

inaugurate

inaugurar
Meaning
To formally begin or introduce something, especially with a ceremony.
Example
The mayor will inaugurate the new bridge tomorrow.
El alcalde inaugurará el nuevo puente mañana.
B2 adjective /ˈɪnfɪnɪt/

infinite

infinito
Meaning
limitless or endless in space, extent, or number
Example
The universe is often described as infinite.
El universo a menudo se describe como infinito.
C1 adjective ˈɪn.tər.ɪm

interim

interino
Meaning
In or for the intervening period; provisional or temporary.
Example
Interim governments manage transitional phases.
Los gobiernos interinos gestionan fases de transición.
C1 noun/verb /ˈɪnsɛns/

incense

incienso / enfurecer
Meaning
a substance burned for its sweet smell (noun); to make very angry (verb)
Example
The smell of incense filled the temple, but his rude words incensed her.
El olor del incienso llenó el templo, pero sus palabras groseras la enfurecieron.
C1 noun ˌɪrɪˈvɜːrsəbl ˈdæmɪdʒ

irreversible damage

daño irreversible
Meaning
Harm or injury that cannot be undone or repaired.
Example
Climate change causes irreversible damage to ecosystems.
El cambio climático causa daño irreversible a los ecosistemas.
C2 adjective /ɪmˈprɛɡnəbl̩/

impregnable

impenetrable
Meaning
Unable to be captured, broken into, or defeated.
Example
The fortress was considered impregnable by the enemy.
La fortaleza fue considerada impenetrable por el enemigo.
B2 adjective /ɪnˈfɪə.ri.ər/

inferior

inferior
Meaning
Of lower quality, rank, or status.
Example
This material is inferior to the one we used before.
Este material es inferior al que usamos antes.
C2 noun /ɪˈrɛvərəns/

irreverence

irreverencia
Meaning
a lack of respect for people or things that are generally taken seriously
Example
His jokes about religion showed irreverence to the sacred traditions.
Sus bromas sobre religión mostraron irreverencia hacia las tradiciones sagradas.
C2 noun /ɪˈreɪdiəns/

irradiance

irradiancia
Meaning
the quality of shining brightly; the intensity of light falling on a surface
Example
The irradiance of the sun at noon was overwhelming.
La irradiancia del sol al mediodía era abrumadora.
C1 adjective /ˌɪn.səˈbɔːr.dɪ.nət/

insubordinate

insubordinado
Meaning
Defiant of authority; disobedient to orders.
Example
The insubordinate employee refused to follow the manager's instructions.
El empleado insubordinado se negó a seguir las instrucciones del gerente.