impurity
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C1 noun /ɪmˈpjʊərəti/

impurity

impureza
Meaning
the state of being unclean or contaminated; a substance that makes something impure
Example
The scientist removed every impurity from the water sample.
El científico eliminó toda impureza de la muestra de agua.
B2 adjective ˌɪnstrəˈmɛntl

instrumental

instrumental
Meaning
Serving as a crucial means, agent, or tool; having a part in bringing about a result.
Example
Children can be instrumental in building a better society.
Los niños pueden ser instrumentales en la construcción de una sociedad mejor.
B2 noun ˌɪr.ɪˈɡeɪ.ʃən

irrigation

riego
Meaning
The artificial application of water to land or soil.
Example
Irrigation systems improve crop yields in dry regions.
Los sistemas de riego mejoran los rendimientos de los cultivos en regiones secas.
C2 adjective /ˌɪrɪˈkɒnsɪləbl/

irreconcilable

irreconciliable
Meaning
impossible to make compatible or bring into harmony; unable to resolve differences
Example
The couple separated due to irreconcilable differences.
La pareja se separó debido a diferencias irreconciliables.
A2 noun/verb /ˈaɪən/ or /ˈaɪərn/

iron

hierro / plancha
Meaning
a strong, hard metal used in construction; also to press clothes with heat
Example
He used an iron to smooth his shirt.
Él usó una plancha para alisar su camisa.
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 /ˌɪndɪˈsaɪsɪv/

Indecisive

indeciso
Meaning
unable to make decisions quickly; hesitant; wavering
Example
She was indecisive about which university to attend.
Ella estaba indecisa sobre qué universidad asistir.
C1 noun /ˈɪnkwest/

inquest

investigación
Meaning
A legal or official inquiry, especially into the cause of a death.
Example
The inquest revealed the cause of the accident.
La investigación reveló la causa del accidente.
C2 noun /ɪmˈpʌlʃən/

impulsion

impulso
Meaning
a strong urge or drive to act; the act of impelling
Example
His impulsion to travel made him leave his job suddenly.
Su impulso de viajar lo llevó a dejar su trabajo de repente.
C2 adjective /ɪnˈkɒrɪdʒəbəl/

incorrigible

incorregible
Meaning
incapable of being corrected, improved, or reformed
Example
He is an incorrigible optimist who never loses hope.
Él es un optimista incorregible que nunca pierde la esperanza.
B2 verb /ɪnˈʃʊər/

insure

asegurar
Meaning
to provide insurance; to make certain
Example
I need to insure my new car.
Necesito asegurar mi coche nuevo.
C2 adjective /aɪˈsɒ.krə.nəs/

isochronous

aconteciendo a intervalos de tiempo iguales
Meaning
Occurring at equal time intervals; in unison or synchrony.
Example
The pendulum swings are isochronous, repeating at equal intervals.
Los oscilaciones del péndulo son isócronos, repitiendo a intervalos iguales.
B1 adjective /ˈɪnər/

inner

interno
Meaning
Located inside or closer to the center; relating to one’s thoughts or feelings.
Example
She shared her inner thoughts with her best friend.
Ella compartió sus pensamientos internos con su mejor amiga.
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.
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.
C1 noun /ˈɪmɪnəns/

imminence

inminencia, estado de proximidad
Meaning
the state of being about to happen
Example
The imminence of the storm forced people to take shelter.
La inminencia de la tormenta obligó a la gente a buscar refugio.
C2 verb /ɪˈnjʊər/

inure

acostumbrar
Meaning
To become accustomed to something, especially something unpleasant.
Example
Soldiers quickly became inured to the harsh conditions.
Los soldados rápidamente se acostumbraron a las duras condiciones.
C1 adjective /ˌɪnkənˈkluːsɪv/

inconclusive

inconcluso
Meaning
Not leading to a definite result or decision.
Example
The investigation remained inconclusive due to a lack of evidence.
La investigación permaneció inconclusa debido a la falta de evidencia.
C1 adjective /ɪnˈhjuːmən/

Inhuman

inhumano
Meaning
lacking human qualities; cruel; brutal; savage
Example
The dictator's inhuman treatment of prisoners shocked the international community.
El trato inhumano del dictador hacia los prisioneros sorprendió a la comunidad internacional.
B1 verb ɪnˈkriːsɪŋ

increasing

creciente
Meaning
Becoming or making greater in size, amount, intensity, or degree; growing.
Example
Increasing awareness about education is necessary.
Aumentar la conciencia sobre la educación es necesario.
C1 verb /ɪmˈbɛd/

imbed

incrustar
Meaning
To fix firmly or deeply in a surrounding mass.
Example
The journalist imbedded himself with the troops to report firsthand.
El periodista se incrustó con las tropas para reportar de primera mano.
C2 noun /ˈɪndɪkənt/

indicant

indicador
Meaning
Something that indicates or points to a fact or condition.
Example
High fever is often an indicant of infection.
La fiebre alta a menudo es un indicador de infección.
C1 adjective /ɪmˈprɒmp.tjuː/

impromptu

imprevisto
Meaning
Done without being planned, organized, or rehearsed; spontaneous.
Example
He gave an impromptu speech at the event.
Él dio un discurso improvisado en el evento.
C2 adjective /ˌɪntərˈlɒkjətəri/

interlocutory

provisional
Meaning
Given during the course of a legal action, not final but temporary or provisional.
Example
The judge issued an interlocutory order to maintain the status quo until the hearing.
El juez emitió una orden provisional para mantener el statu quo hasta la audiencia.
C1 adjective /ɪnˈhɛrənt/

inherent

inherente
Meaning
Existing in something as a natural, permanent, or essential quality.
Example
There are inherent risks in extreme sports.
Existen riesgos inherentes en los deportes extremos.
C1 adjective /ˈɪɡ.ni.əs/

igneous

ígnea
Meaning
Formed through the cooling and solidification of magma or lava.
Example
Granite is an igneous rock commonly used in construction.
El granito es una roca ígnea que se utiliza comúnmente en la construcción.
C2 verb /ɪnˈfætʃueɪt/

infatuate

embelesar
Meaning
to inspire with an intense but short-lived passion or admiration
Example
He was infatuated with her beauty.
Él estaba fascinado por su belleza.
C1 noun /ɪmˈpɛdɪmənt/

impediments

obstáculos
Meaning
A hindrance or obstruction in doing something; things that prevent progress or achievement.
Example
Economic impediments often hinder social development.
Los obstáculos económicos a menudo dificultan el desarrollo social.
A2 noun /ˈɪntəvjuː/

interview

entrevista
Meaning
A meeting of people face to face, especially for consultation.
Example
The interview was conducted in a calm and professional manner.
La entrevista se llevó a cabo de manera tranquila y profesional.
B2 verb /ɪmˈpoʊzd/

imposed

impuesto
Meaning
forced something to be accepted or put in place
Example
The government imposed new regulations on the industry.
El gobierno impuso nuevas regulaciones sobre la industria.
B1 noun /ˈɪnpʊt/

input

entrada, información proporcionada
Meaning
information, advice, or data that is put into a system, device, or process
Example
The manager asked for everyone's input on the new project.
El gerente pidió la opinión de todos sobre el nuevo proyecto.
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 adjective /ɪmˈpjʊər/

Impure

impuro
Meaning
contaminated; not clean; mixed with foreign substances
Example
The impure water caused health problems in the village.
El agua impura causó problemas de salud en el pueblo.
C2 adjective /ɪmˈpɔːrtʃənət/

importunate

importuno
Meaning
Persistent to the point of annoyance or intrusion
Example
The importunate salesman kept calling despite repeated refusals.
El vendedor importuno siguió llamando a pesar de las repetidas negativas.
C1 noun /ˌɪn.səˌbɔːr.dɪˈneɪ.ʃən/

insubordination

insubordinación
Meaning
Defiance of authority; refusal to obey orders.
Example
The soldier was punished for insubordination during the mission.
El soldado fue castigado por insubordinación durante la misión.
C1 noun /ɪmˈpɒs.tər/

Impostor

impostor; fraude
Meaning
a person who pretends to be someone else in order to deceive others; a fraud
Example
The impostor convinced everyone he was a doctor until his fake credentials were discovered.
El impostor convenció a todos de que era un doctor hasta que se descubrió que sus credenciales eran falsas.
C1 noun /ɪnˈsæn.ə.ti/

Insanity

locura; demencia
Meaning
the state of being seriously mentally ill; extreme foolishness or irrationality
Example
The defense lawyer argued that his client was not guilty by reason of insanity.
El abogado defensor argumentó que su cliente no era culpable por razón de locura.
C2 noun /ɪˈrʌp.ʃən/

Irruption

una entrada violenta repentina; una invasión o incursión; una explosión o erupción repentina
Meaning
a sudden violent entry; an invasion or raid; a sudden outburst or eruption
Example
The army's irruption into enemy territory caught the opposing forces completely off guard.
La irrupción del ejército en el territorio enemigo sorprendió completamente a las fuerzas opuestas.
B2 verb /ɪnˈheɪl/

inhale

inhalar
Meaning
to breathe in; to draw air into the lungs
Example
Take a deep breath and inhale slowly.
Toma una respiración profunda e inhala lentamente.
B2 verb /ˈɪnəveɪt/

innovate

innovar
Meaning
To introduce new methods, ideas, or products.
Example
The company must innovate to stay ahead of its competitors.
La empresa debe innovar para mantenerse por delante de sus competidores.
B2 noun /ˌɪnstəˈbɪləti/

instability

inestabilidad
Meaning
lack of stability or balance; tendency to change, fail, or collapse easily
Example
Political instability has slowed economic growth in the region.
La inestabilidad política ha ralentizado el crecimiento económico de la región.
C1 noun ˌɪnsjʊˈleɪʃən

insulation

aislamiento
Meaning
Material used to prevent heat, sound, or electricity from being transmitted from one area to another.
Example
Insulation of food storage areas can prevent pests from entering.
El aislamiento de las áreas de almacenamiento de alimentos puede evitar que entren plagas.
B2 verb /ɪnˈtriːɡ/

intrigue

intrigar
Meaning
to arouse curiosity or interest; to make someone fascinated
Example
The mystery novel will intrigue any reader.
La novela de misterio intriga a cualquier lector.
C1 adjective /ˌɪnsərˈmaʊntəbl/

insurmountable

insuperable
Meaning
Too great to be overcome.
Example
The explorers faced insurmountable odds in the desert.
Los exploradores enfrentaron obstáculos insuperables en el desierto.
C2 noun /ˈaɪ.lət/

islet

islote
Meaning
A very small island.
Example
The fishermen rested on a tiny islet before continuing their journey.
Los pescadores descansaron en un islote pequeño antes de continuar su viaje.
C2 adjective /ˌɪrɛvəˈrɛnʃəl/

irreverential

irreverente
Meaning
Showing a lack of respect for things that are generally taken seriously.
Example
His irreverential humor often shocked traditional audiences.
Su humor irreverente a menudo sorprendía a las audiencias tradicionales.
C1 adjective /ˌɪnɔːrˈɡænɪk/

inorganic

inorgánico
Meaning
relating to substances that are not derived from living organisms; lacking organic structure or growth
Example
Inorganic compounds are commonly studied in chemistry labs.
Los compuestos inorgánicos se estudian en los laboratorios.
C1 verb /ɪnˈtɒksɪkeɪt/

intoxicate

felicidad
Meaning
to make someone lose control of their faculties or behavior due to alcohol or drugs
Example
The strong drink quickly intoxicated him.
No pudo esconder su felicidad cuando recibió el premio.
C2 noun /ˌɪmbəˈsɪləti/

imbecility

imbecilidad
Meaning
Extreme foolishness, stupidity, or weakness of mind.
Example
The plan was abandoned due to its sheer imbecility.
El plan fue abandonado debido a su pura imbecilidad.
C1 noun /ˌɪntərˈmɪʃən/

intermission

intermedio
Meaning
A pause or break, especially during a performance or event.
Example
The play had a twenty-minute intermission.
La obra tuvo un intermedio de veinte minutos.
C2 adjective /ˌɪlˈneɪ.tʃəd/

ill-natured

de mal carácter
Meaning
Having a bad or unpleasant character; unkind or malicious.
Example
He made an ill-natured remark about his colleague.
Hizo un comentario de mal carácter sobre su colega.
C1 adjective /ɪnˈdʌstriəs/

industrious

trabajador
Meaning
Hardworking and diligent in one's duties.
Example
She is an industrious student who always completes her assignments on time.
Ella es una estudiante trabajadora que siempre completa sus tareas a tiempo.
C2 noun /ˌɪn.strəˈmɛn.təl.ɪst/

instrumentalist

instrumentista
Meaning
A person who plays a musical instrument.
Example
The instrumentalist played a beautiful solo on the violin.
El instrumentista tocó un hermoso solo en el violín.
B2 noun /ˌɪmpərˈfɛkʃən/

imperfection

imperfección
Meaning
a flaw, defect, or weakness; the state of being imperfect
Example
She accepted her imperfection as part of being human.
Ella aceptó su imperfección como parte de ser humana.
C1 adjective /ɪnˈtɒl.ər.ə.bəl/

Intolerable

intolerable
Meaning
unable to be endured; extremely unpleasant or painful
Example
The noise from the construction site was intolerable.
El ruido de la obra de construcción era intolerable.
C2 noun /ˌɪnkrɪˈdjuːləti/

incredulity

incredulidad
Meaning
the state of being unwilling or unable to believe something
Example
She looked at him with incredulity after hearing the strange story.
Ella lo miró con incredulidad después de escuchar la extraña historia.
B2 adjective ˈɪn.tɪ.ɡreɪ.tɪd

integrated

integrado
Meaning
Combining or coordinating separate elements so as to provide a harmonious, interrelated whole.
Example
Integrated systems optimize efficiency.
Los sistemas integrados optimizan la eficiencia.
C2 verb /ɪnˈsteɪt/

instate

instaurar
Meaning
To set up in position, office, or authority.
Example
The board decided to instate her as the new director.
La junta decidió instatarla como la nueva directora.
C2 verb /ɪnˈdaɪt/

indite

componer
Meaning
To write or compose (literary or formal works).
Example
The poet indited a heartfelt sonnet.
El poeta compuso un soneto sincero.
C2 adjective /ɪˈlɪbərəl/

illiberal

iliberal
Meaning
Opposed to liberal principles; restricting freedom of thought or behavior.
Example
The government was criticized for its illiberal policies.
El gobierno fue criticado por sus políticas iliberales.
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.
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 noun /ˌɪntɪˈmeɪʃən/

intimation

insinuación
Meaning
A subtle or indirect hint or suggestion.
Example
She gave no intimation of her plans.
Ella no dio ninguna insinuación sobre sus planes.
B2 verb /ˈɪl.ə.streɪt/

illustrate

ilustrar
Meaning
to explain or make something clear by using examples, pictures, or comparisons
Example
The teacher used diagrams to illustrate the concept.
El maestro utilizó diagramas para ilustrar el concepto.
C1 verb /ɪmˈpɛər/

impair

deteriorar
Meaning
to weaken or damage something, especially a function or ability
Example
Smoking can impair your lung capacity.
Fumar puede dañar tu capacidad pulmonar.
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.
C1 adjective /ɪnˈdʌldʒənt/

indulgent

indulgente
Meaning
Having a tendency to be overly generous or lenient with someone.
Example
The indulgent mother allowed her child to stay up late.
La madre indulgente permitió que su hijo se quedara despierto hasta tarde.
C2 noun /ɪnˈsuːsiəns/

insouciance

despreocupación
Meaning
Casual lack of concern; indifference.
Example
She carried herself with an air of insouciance, unbothered by the challenges ahead.
Ella caminaba con un aire de despreocupación, sin preocuparse por los desafíos que venían.
C1 adjective /ˌaɪ.di.əˈlɒdʒ.ɪ.kəl/

ideological

ideológico
Meaning
Relating to or based on a system of ideas or beliefs.
Example
The two parties are divided by deep ideological differences.
Las dos partes están divididas por profundas diferencias ideológicas.
C1 noun /ɪmˈpɜːrtɪnəns/

impertinence

impertinencia
Meaning
lack of respect; rudeness
Example
The teacher was shocked by the student's impertinence.
El maestro se sorprendió por la impertinencia del estudiante.
C1 noun /ɪmˈbæl.əns/

Imbalance

desequilibrio
Meaning
lack of proportion or relation between corresponding things; unequal distribution
Example
The doctor said the patient's dizziness was caused by an inner ear imbalance.
El doctor dijo que el mareo del paciente fue causado por un desequilibrio en el oído interno.
C1 verb /ˈɪnsjuleɪt/

insulate

aislar
Meaning
To protect something by covering it, especially to prevent heat, sound, or electricity from escaping or entering.
Example
The house was insulated to reduce heating costs.
La casa fue aislada para reducir los costos de calefacción.
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.
C2 adjective ɪnˈdɒm.ɪ.tə.bəl

indomitable

indomable
Meaning
Impossible to subdue or defeat.
Example
Her indomitable spirit helped her overcome adversity.
Su espíritu indomable la ayudó a superar la adversidad.
C2 adjective /ɪnˈtræn.sɪ.dʒənt/

intransigent

intransigente, terco, obstinado
Meaning
Unwilling or refusing to change one's views or to agree about something.
Example
His intransigent stance delayed the agreement.
Su postura intransigente retrasó el acuerdo.
A2 adjective/noun /ˈɪndiən/

indian

indio
Meaning
Relating to India, its people, or their culture.
Example
She loves Indian food, especially biryani.
A ella le encanta la comida india, especialmente el biryani.
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.
C2 noun /ˌɪnˌkeɪpəˈbɪləti/

incapability

incapacidad
Meaning
lack of ability or power to do something; inability or incompetence
Example
His incapability to manage the team led to serious problems.
Su incapacidad para gestionar el equipo provocó problemas graves.
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.
C1 adjective ˌɪn.krəˈmen.təl

incremental

incremental
Meaning
Relating to or denoting an increase or addition, especially one of a series on a fixed scale; proceeding in small stages.
Example
Incremental changes ensure sustainability.
Los cambios incrementales aseguran la sostenibilidad.
C2 noun /ɪnˈɡrætɪˌtjuːd/

ingratitude

ingratitud
Meaning
Lack of gratitude; failure to show thanks or appreciation.
Example
His ingratitude hurt her feelings after all she had done for him.
Su ingratitud le dolió después de todo lo que ella había hecho por él.
B1 noun /ɪmˈprɛʃən/

impression

impresión, concepto
Meaning
an idea, feeling, or opinion about something or someone
Example
The book gave me a good first impression.
El libro me dio una buena primera impresión.
B2 adjective /ˌɪd.iˈɒt.ɪk/

Idiotic

idiota
Meaning
extremely stupid; foolish; senseless
Example
His idiotic behavior embarrassed everyone at the meeting.
Su comportamiento idiota avergonzó a todos en la reunión.
B2 verb ɪnˈvɛst.ɪŋ

investing

invertir
Meaning
The act of putting money into financial schemes, shares, property, or a commercial venture with the expectation of achieving a profit.
Example
Investing in stocks can generate long-term wealth.
Invertir en acciones puede generar riqueza a largo plazo.
C1 noun /ˈɪrɪtənt/

irritant

sustancia irritante
Meaning
something that causes irritation or discomfort
Example
Dust is a common irritant for people with allergies.
El polvo es un irritante común para las personas con alergias.
C2 noun /ɪnˈtɛmpərəns/

intemperance

intemperancia
Meaning
Lack of moderation or self-control, especially with drinking or eating.
Example
His intemperance in drinking ruined his health.
Su intemperancia al beber arruinó su salud.
A2 noun /ˌɪnvɪˈteɪʃən/

invitation

felicidad
Meaning
a written or spoken request to attend an event or to participate in something
Example
She sent me an invitation to her wedding.
Ella no pudo ocultar su felicidad cuando recibió el premio.
C2 noun /ˌɪrɪˈdɛsəns/

iridescence

brillo iridiscente
Meaning
a play of lustrous, changing colors like those of a rainbow
Example
The butterfly's wings shimmered with iridescence.
Las alas de la mariposa brillaban con brillo iridiscente.
B2 noun ˈɪnər strɛŋkθ

inner strength

fuerza interior
Meaning
Mental or spiritual power that helps a person cope with difficulties.
Example
Community service fosters inner strength in individuals.
El servicio comunitario fomenta la fuerza interior en los individuos.
C2 adjective /ɪnˈsɛnseɪt/

insensate

insensible
Meaning
lacking physical sensation or empathy; without feeling or sensitivity
Example
The dictator's insensate cruelty shocked the world.
La crueldad insensible del dictador sorprendió al mundo.
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.
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.
B1 abbreviation /ˌaɪˈiː/

ie

es decir
Meaning
That is to say; used to clarify or explain something more precisely.
Example
Many amphibians, i.e., frogs and salamanders, can live both in water and on land.
Muchos anfibios, es decir, ranas y salamandras, pueden vivir tanto en agua como en tierra.
C2 adjective /ɪˈrɛfrəɡəbəl/

irrefragable

irrefutable
Meaning
Impossible to refute, deny, or break
Example
The lawyer presented irrefragable evidence that proved his client’s innocence.
El abogado presentó pruebas irrefutables que demostraron la inocencia de su cliente.
C2 noun /ˈɪntərˌloʊpər/

interloper

intruso
Meaning
A person who becomes involved in a situation or place where they are not wanted.
Example
He felt like an interloper at the private family gathering.
Se sintió como un intruso en la reunión familiar privada.
C2 conjunction /ˌɪnəzˈmʌtʃ æz/

inasmuch-as

ya que
Meaning
Because; since.
Example
He cannot attend, inasmuch as he is unwell.
Él no puede asistir, ya que está enfermo.
C2 adjective /ˌɪndɪˈfætɪɡəbl̩/

indefatigable

inagotable
Meaning
persisting tirelessly; incapable of being fatigued
Example
Her indefatigable spirit kept the team motivated during the long project.
Su espíritu inagotable mantuvo al equipo motivado durante el largo proyecto.
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.
C2 adjective /ɪnˈseɪʃiət/

insatiate

insaciable
Meaning
impossible to satisfy; always wanting more
Example
He had an insatiate desire for power.
Él tenía un deseo insaciable de poder.
C2 adjective /ˌɪnfəˈlɪsɪtəs/

infelicitous

inadecuado
Meaning
not suitable or well chosen; awkward or unfortunate
Example
His infelicitous remark ruined the atmosphere of the meeting.
Su comentario inadecuado arruinó el ambiente de la reunión.
B2 adjective /ɪˈlɪt.ər.ət/

Illiterate

analfabeto; iletrado; ignorante
Meaning
unable to read or write; lacking education
Example
The program aims to help illiterate adults learn to read and write.
El programa tiene como objetivo ayudar a los adultos analfabetos a aprender a leer y escribir.
C2 noun /ɪmˈpruː.dəns/

Imprudence

imprudencia; descuido; temeridad
Meaning
the quality of being imprudent; lack of care for consequences; recklessness
Example
His financial imprudence led to bankruptcy within just two years.
Su imprudencia financiera llevó a la quiebra en solo dos años.
C2 noun /ɪnˈfriːkwəns/

infrequence

infrecuencia
Meaning
The state of occurring rarely or at long intervals.
Example
The infrequence of their meetings made it hard to maintain close ties.
La infrecuencia de sus reuniones hacía difícil mantener vínculos cercanos.
C1 noun ˌɪnfɛsˈteɪʃən

infestation

infestación, gran número de insectos o animales en un lugar
Meaning
The presence of an unusually large number of insects or animals in a place, causing damage or disease.
Example
The infestation of ants in the kitchen led to immediate pest control measures.
La infestación de hormigas en la cocina llevó a medidas inmediatas de control de plagas.
C1 adverb /ˈɪnwərdli/

inwardly

por dentro
Meaning
In the mind or spirit; not outwardly visible.
Example
She smiled outwardly but inwardly she was worried.
Ella sonrió por fuera, pero por dentro estaba preocupada.
C2 noun /ˌɪntərˈsɛsər/

intercessor

intercesor
Meaning
a person who intervenes or pleads on behalf of another
Example
He acted as an intercessor to resolve the conflict between the two families.
Él actuó como un intercesor para resolver el conflicto entre las dos familias.
C2 adjective /ɪnˈɛstɪməbl/

inestimable

invaluable
Meaning
Too great or valuable to be measured or estimated.
Example
Her contribution to the project was of inestimable value.
Su contribución al proyecto fue de un valor invaluable.
C1 noun /ˈɪm.pæs/

impasse

impasse
Meaning
A situation where no progress is possible.
Example
The negotiations reached an impasse, delaying the agreement.
Las negociaciones llegaron a un impasse, retrasando el acuerdo.
C1 adjective /ɪnˈsʌf.ər.ə.bəl/

insufferable

insoportable
Meaning
Too extreme to bear; intolerable.
Example
The heat during the summer was insufferable.
El calor durante el verano fue insoportable.
C2 noun (compound/erroneous entry) /ɪnˈɛksərəbl ɑːrmi/

inexorableinexorablearmy

ejército imparable
Meaning
This appears to be a corrupted or concatenated form; interpreted as 'inexorable army' — an unstoppable or relentless force.
Example
The rebels feared the inexorable army approaching their stronghold.
Los rebeldes temían al ejército imparable que se acercaba a su fortaleza.
C1 noun ˌɪm.pʌlˈsɪv.ɪ.ti

impulsivity

impulsividad
Meaning
The tendency to act quickly and without thought or care; lack of self-control.
Example
His impulsivity led him to make reckless choices.
Su impulsividad lo llevó a tomar decisiones imprudentes.
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.
B1 verb /aɪˈdentɪfaɪ/

identify

identificar
Meaning
to recognize; to establish who someone is
Example
Can you identify the suspect?
¿Puedes identificar al sospechoso?
B1 adjective ɪnˈdʌs.tri.əl

industrial

industrial
Meaning
Relating to or characterized by industry.
Example
Industrial sectors boost exports.
Los sectores industriales aumentan las exportaciones.
C1 noun /ɪnˈdjuːsmənt/

inducement

inducido
Meaning
something that persuades or encourages someone to do something
Example
The company offered a bonus as an inducement to employees.
La empresa ofreció un bono como incentivo para los empleados.
C1 adjective ˌɪm.pəˈsɛp.tɪ.bəl

imperceptible

imperceptible
Meaning
So subtle or gradual that it is difficult to notice or perceive
Example
The changes in his behavior were imperceptible at first.
Los cambios en su comportamiento eran imperceptibles al principio.
C2 adjective /ˌɪnæprɪˈhɛnsəbl/

inapprehensible

incomprensible
Meaning
not understandable; incomprehensible
Example
The concept was so abstract that it seemed inapprehensible to most students.
El concepto era tan abstracto que parecía incomprensible para la mayoría de los estudiantes.
C2 noun /ˈaɪdlər/

idler

holgazán
Meaning
A person who avoids work or spends time lazily.
Example
He was known as an idler who wasted his days.
Él era conocido como un holgazán que desperdiciaba sus días.
C1 noun ˌɪnˈsaɪtfʊlnɪs

insightfulness

perspicacia, capacidad de análisis
Meaning
The capacity to gain an accurate and deep intuitive understanding of a person or thing.
Example
His insightfulness helped solve the complex problem.
Su perspicacia ayudó a resolver el problema complejo.
C2 noun /ɪnˈsɪɡniə/

insignia

insignia
Meaning
A badge or symbol that shows rank, position, or membership.
Example
The soldier proudly wore the insignia of his regiment.
El soldado llevaba orgulloso la insignia de su regimiento.
B2 adjective /ˌɪrɪˈzɪstəbəl/

Irresistible

irresistible
Meaning
too attractive and tempting to be resisted; impossible to resist
Example
The chocolate cake was absolutely irresistible.
El pastel de chocolate era absolutamente irresistible.