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All Vocabulary Cards All Vocabularies
C1 noun /ˈaɪsətəʊp/

isotope

Meaning
Atoms of the same element with equal number of protons but different numbers of neutrons.
Example
Carbon-14 is a radioactive isotope used in dating fossils.
C2 adjective /ɪˈnjʊərd/

inured

Meaning
Accustomed to something, especially something unpleasant.
Example
After years of hardship, she was inured to suffering.
C2 adjective /ˈɪkθiɪk/

ichthyic

Meaning
Relating to or resembling fish.
Example
The artist's painting had an ichthyic quality.
B1 verb /ɪnˈfɔ:m/

inform

Meaning
to tell someone about something; to give information
Example
Please inform me when you arrive at the airport.
C2 verb /ɪnˈfætʃueɪt/

infatuate

Meaning
to inspire with an intense but short-lived passion or admiration
Example
He was infatuated with her beauty.
C2 adjective /ˌɪnfəˈlɪsɪtəs/

infelicitous

Meaning
not suitable or well chosen; awkward or unfortunate
Example
His infelicitous remark ruined the atmosphere of the meeting.
C2 adjective /ˌɪn.trəˈmjʊə.rəl/

intramural

Meaning
Occurring within the walls of a single institution, especially a school or college.
Example
The college organizes intramural sports competitions every semester.
C1 noun /ˈɪn.tə.lekt/

intellect

Meaning
The ability to think, reason, and understand objectively.
Example
Her intellect is admired by all her colleagues.
C1 noun /ɪnˈkɒmpɪtəns/

incompetence

Meaning
Lack of ability, skill, or effectiveness in doing something.
Example
The project failed due to the manager’s incompetence.
C1 noun /ˌɪntɪˈmeɪʃən/

intimation

Meaning
A subtle or indirect hint or suggestion.
Example
She gave no intimation of her plans.
C2 noun /ɪnˌtɛl.ɪˈdʒɛntsi.ə/

intelligentsia

Meaning
The group of people engaged in intellectual and cultural pursuits in a society.
Example
The intelligentsia played a key role in shaping public opinion.
C1 adjective /ˈɪnsjələr/

insular

Meaning
Narrow-minded, isolated, or relating to an island.
Example
The community was criticized for its insular attitudes toward outsiders.
C2 adjective /ˌɪndɪˈfætɪɡəbl̩/

indefatigable

Meaning
persisting tirelessly; incapable of being fatigued
Example
Her indefatigable spirit kept the team motivated during the long project.
C1 verb /ɪmˈpɛər/

impair

Meaning
to weaken or damage something, especially a function or ability
Example
Smoking can impair your lung capacity.
C2 adjective /aɪˈdɒlətrəs/

idolatrous

Meaning
Excessively admiring or worshipping someone or something as an idol.
Example
The king was criticized for his idolatrous devotion to wealth.
C2 adjective /ɪnˈɛstɪməbl/

inestimable

Meaning
Too great or valuable to be measured or estimated.
Example
Her contribution to the project was of inestimable value.
B1 noun /ˈɪnpʊt/

input

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.
C2 adjective /ɪmˈpruːdənt/

imprudent

Meaning
Not showing care for the consequences of an action.
Example
It was imprudent to drive in such stormy weather.
C2 adjective /ˌɪrɪˈdjuːsəbl/

irreducible

Meaning
impossible to reduce or simplify further
Example
The fraction 3/7 is irreducible.
C1 adjective /ˈɪnfəməs/

infamous

Meaning
well known for some bad quality or deed
Example
The dictator was infamous for his cruelty.
C1 noun /ˈɪd.i.əm/

idiom

Meaning
A group of words whose meaning is different from the meanings of the individual words.
Example
The idiom 'break the ice' means to start a conversation in a friendly way.
C1 noun /ɪnˈsæn.ə.ti/

Insanity

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.
C2 noun /ˌɪn.trəˈɡreʃ.ən/

introgression

Meaning
The transfer of genetic information from one species to another through repeated backcrossing.
Example
Introgression plays a significant role in plant breeding.
C2 noun /ˈaɪdɪl/

idyll

Meaning
An extremely happy, peaceful, or picturesque episode or scene, often idealized.
Example
Their honeymoon was an idyll on a tropical island.
C2 noun /ˈɪkθiəˌsɔːrz/

ichthyosaurs

Meaning
Extinct marine reptiles that resembled fish and dolphins, dominant during the Mesozoic era.
Example
Ichthyosaurs were swift predators of the ancient seas.
C2 verb /ˈɪməleɪt/

immolate

Meaning
To kill or sacrifice, especially by burning.
Example
The protesters threatened to immolate themselves in front of the building.
C1 verb /ɪnˈsaɪt/

incite

Meaning
to provoke; to stir up
Example
His speech incited the crowd to violence.
C1 adjective /ɪnˈdʌstriəs/

industrious

Meaning
Hardworking and diligent in one's duties.
Example
She is an industrious student who always completes her assignments on time.
A2 noun /ˌɪn.trəˈdʌk.ʃən/

introduction

Meaning
the action of introducing something or someone; an opening or beginning part
Example
The professor gave a brief introduction before starting the lecture.
B2 adjective /ɪnˈvɪz.ə.bəl/

Invisible

Meaning
unable to be seen; not visible to the eye
Example
The bacteria are invisible without a microscope.
C1 noun /ɪnˈsɜːrdʒənt/

insurgent

Meaning
A person who rises in revolt against authority or government.
Example
The army arrested several insurgents after the attack.
C2 adjective /ˌɪrɪˈprəʊtʃəbl̩/

irreproachable

Meaning
Beyond criticism; faultless.
Example
The judge was known for his irreproachable integrity.
B2 noun /ɪnˈtɒlərəns/

intolerance

Meaning
unwillingness to accept or endure beliefs, behaviors, or conditions different from one's own
Example
The leader was criticized for his intolerance toward other religions.
C1 adjective /ˈɪnərmoʊst/

Innermost

Meaning
most private and secret; deepest; most personal
Example
She shared her innermost feelings with her closest friend.
C2 adjective /ɪnˈtɛmpərət/

intemperate

Meaning
Lacking self-control; immoderate, especially in indulgence.
Example
The politician's intemperate remarks caused controversy.
C2 adjective /ɪmˈplækəbl/

implacable

Meaning
unable to be appeased, calmed, or pacified
Example
The soldiers faced an implacable enemy who refused to surrender.
B2 verb ɪnˈvɛst.ɪŋ

investing

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.
C1 verb /ɪnˈterəˌɡeɪt/

interrogate

Meaning
to ask someone questions in a thorough and formal way; to question intensively
Example
The police interrogated the suspect for hours.
B2 noun ˈɪn.deks

index

Meaning
An alphabetical list of names, subjects, etc. with references to the places where they occur, typically found at the end of a book; a sign or measure of something.
Example
An index organizes critical data.
B1 verb ɪnˈspaɪər

inspire

Meaning
To fill someone with the urge or ability to do or feel something, especially creative or noble.
Example
Artemis seeks to inspire future generations.
B2 noun /ɪsˈlɑːm/

islam

Meaning
the religion founded by the Prophet Muhammad, based on belief in one God (Allah)
Example
Islam emphasizes peace, justice, and compassion.
C1 adjective /ɪnˈɡreɪnd/

ingrained

Meaning
Firmly fixed or established; deeply rooted and difficult to change.
Example
His ingrained habits were hard to break.
B2 adverb /ˌɪndəˈrɛktli/

indirectly

Meaning
in a way that is not direct; through an intermediate means or influence
Example
The policy affected small businesses indirectly.
B1 noun aɪˈdɛntɪti

identity

Meaning
The fact of being who or what a person or thing is; the characteristics determining who or what a person or thing is.
Example
The day reinforces our national identity.
C1 adjective /ˌɪntərˈtʃeɪndʒəbl/

interchangeable

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.
C2 adjective /ˌɪndaɪˈdʒestəbəl/

Indigestible

Meaning
difficult or impossible to digest; hard to process in the stomach
Example
The old bread became hard and indigestible.
C1 verb /ɪmˈpɛl/

impel

Meaning
to drive, force, or urge someone to do something
Example
Her curiosity impelled her to open the mysterious box.
C1 adjective /ɪnˈhɪbɪtɪd/

inhibited

Meaning
Unable to act in a relaxed and natural way, especially due to self-consciousness or restraint.
Example
He was too inhibited to express his true feelings.
C1 noun /ɪmˈpɒs.tər/

Impostor

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.
C2 adjective /ɪˈrædɪkəbəl/

irradicable

Meaning
not able to be eradicated; impossible to destroy or remove completely
Example
The love of a mother for her child is irradicable.
B2 adjective /ɪmˈprɒp.ər/

Improper

Meaning
inappropriate; incorrect; not suitable
Example
It would be improper to discuss personal matters in a business meeting.
C1 adjective /ˌɪnækˈsɛsəbl/

inaccessible

Meaning
unable to be reached, entered, or understood
Example
The remote village is almost inaccessible during the rainy season.
C1 adverb ɪnˈtrɪn.zɪ.kli

intrinsically

Meaning
In a way that is naturally or inherently part of something's essential nature.
Example
Some people are intrinsically motivated to learn.
C1 verb /ˌɪntəˈsɛkt/

intersect

Meaning
to cross or pass through each other
Example
The two roads intersect at the city center.
C1 noun /ɪmˈpɜːrtɪnəns/

impertinence

Meaning
lack of respect; rudeness
Example
The teacher was shocked by the student's impertinence.
B1 verb /ɪnˈvɛnt/

invent

Meaning
to create or design something that has not existed before
Example
Thomas Edison invented the electric bulb.
C1 adjective /ɪmˈpæsəbəl/

impassable

Meaning
Impossible to travel along or over.
Example
The road became impassable after the heavy snowfall.
C1 adjective /ɪnˈveə.ri.ə.bəl/

Invariable

Meaning
never changing; constant; always the same
Example
His invariable routine includes morning exercise and coffee.
C1 verb /ɪnˈvælɪdeɪt/

invalidate

Meaning
To make something not valid or legally acceptable.
Example
The new evidence may invalidate the previous ruling.
C2 verb /ɪˈluːmɪn/

illumine

Meaning
to light up or make clear
Example
The rising sun illumined the mountain peaks.
B1 adjective /ɪmˈpres.ɪv/

Impressive

Meaning
striking; remarkable; having the ability to impress
Example
Her impressive performance earned her a standing ovation.
C1 noun /ɪnˈdem.nə.ti/

Indemnity

Meaning
security or protection against a loss or other financial burden; compensation for damage or loss
Example
The insurance company provided full indemnity for the damages caused by the flood.
C2 adjective /ɪmˈprɒvɪdənt/

improvident

Meaning
Not having or showing foresight; spending wastefully or without thought for the future.
Example
His improvident habits left him with no savings.
C1 verb /ˈɪnkjʊˌbeɪt/

incubate

Meaning
to keep eggs, cells, or organisms at the right conditions for development
Example
The hen will incubate the eggs until they hatch.
C2 adjective /ˌɪrɪˈdɛsənt/

iridescent

Meaning
showing luminous colors that seem to change when seen from different angles
Example
She wore an iridescent dress that sparkled in the light.
B2 adjective /ˈɪn.tɪ.mət/

Intimate

Meaning
close in friendship; private and personal; detailed knowledge
Example
They have an intimate friendship that has lasted for decades.
B2 adjective /aɪˈrɒnɪk/

ironic

Meaning
happening in the opposite way to what is expected, often amusing or sarcastic
Example
It is ironic that the fire station burned down.
C1 verb /ˈɪmplɪˌkeɪt/

implicate

Meaning
To show someone’s involvement in a crime or wrongdoing.
Example
The evidence implicated several officials in the scandal.
C1 verb /ɪˈmɔːrtəlaɪz/

immortalize

Meaning
to preserve the memory of someone or something forever
Example
The statue was built to immortalize the hero’s sacrifice.
C2 verb /ˌɪnkəˈpæsɪteɪt/

incapacitate

Meaning
to deprive someone or something of the ability or strength to function
Example
The severe injury incapacitated the player for the rest of the season.
C1 noun /ɪnˈfɜː.mə.ti/

Infirmity

Meaning
physical or mental weakness; a disease or ailment; frailty
Example
Despite his advanced age and various infirmities, he remained mentally sharp and alert.
C2 noun /ɪnˈtɜːrmənt/

interment

Meaning
The act of burying a dead body in a grave or tomb.
Example
The interment took place at the family cemetery.
C2 verb /ˌɪntərˈpoʊz/

interpose

Meaning
To place or insert between one thing and another; to intervene in a situation.
Example
He quickly interposed himself between the fighters to stop the quarrel.
C1 adjective /ˈɪɡ.ni.əs/

igneous

Meaning
Formed through the cooling and solidification of magma or lava.
Example
Granite is an igneous rock commonly used in construction.
C1 adjective, noun /ɪnˈdɪkətɪv/

indicative

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.
C1 adjective /ɪˈledʒ.ə.bəl/

illegible

Meaning
Not clear enough to be read; unreadable.
Example
The doctor’s handwriting was almost illegible.
C2 adjective /ɪˈnɪkwɪtəs/

iniquitous

Meaning
grossly unfair and morally wrong
Example
Slavery was one of the most iniquitous practices in history.
C2 adjective /ˌɪnsəˈprɛsəbl/

insuppressible

Meaning
That cannot be suppressed or restrained.
Example
She had an insuppressible urge to laugh during the ceremony.
C1 adjective /ɪnˈtɒl.ər.ə.bəl/

Intolerable

Meaning
unable to be endured; extremely unpleasant or painful
Example
The noise from the construction site was intolerable.
C1 verb ɪˈmɜːrs

immerse

Meaning
To involve oneself deeply in a particular activity or interest; to surround completely.
Example
Immerse yourself in the new language.
C1 adjective /ɪnˈtɜːrmənəbl/

interminable

Meaning
Seemingly endless; having no apparent end.
Example
The meeting felt interminable and exhausting.
C1 noun ɪnˌten.sɪ.fɪˈkeɪ.ʃən

intensification

Meaning
The process of becoming or making something more intense or extreme.
Example
The intensification of climate change requires urgent action.
C1 noun/verb /ˈɪnsɛns/

incense

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.
B2 adjective ˌɪn.təˈræk.tɪv

interactive

Meaning
Allowing a two-way flow of information between it and a user, responding to the user's input.
Example
Interactive learning keeps students engaged in lessons.
B2 adjective /ɪnˈædɪkwət/

inadequate

Meaning
Not sufficient or good enough.
Example
The funding was inadequate to complete the project.
C1 adverb /ˈɪnwərdli/

inwardly

Meaning
In the mind or spirit; not outwardly visible.
Example
She smiled outwardly but inwardly she was worried.
C1 adjective /ɪnˈfriːkwənt/

infrequent

Meaning
Happening rarely or not often.
Example
He made infrequent visits to his hometown after moving abroad.
C2 noun /ˈɪndələns/

indolence

Meaning
Avoidance of activity or exertion; laziness.
Example
His indolence kept him from finishing the project on time.
C2 adjective /ˌɪnˈekspɜːrt/

inexpert

Meaning
not skilled or experienced; lacking expertise
Example
The inexpert handling of the machine caused several mistakes.
C2 adjective /ɪnˈsuːpərəbl/

insuperable

Meaning
Impossible to overcome or surpass.
Example
The team faced insuperable challenges during the expedition.
C1 noun /ɪmˈpɛdɪmənt/

impediments

Meaning
A hindrance or obstruction in doing something; things that prevent progress or achievement.
Example
Economic impediments often hinder social development.
C1 verb /ɪnˈstɪl/

instill

Meaning
to gradually but firmly establish an idea, attitude, or habit in someone's mind
Example
Parents try to instill good values in their children.
C2 noun /ɪnˈvaɪtər/

invitor

Meaning
a person who invites someone to an event, meeting, or place
Example
The invitor greeted all the guests warmly at the entrance.
C1 adjective /ˌɪndɪˈstrʌktəbl/

indestructible

Meaning
Impossible to destroy or break.
Example
The superhero's shield was said to be indestructible.
C1 noun /ɪmˈprɪzənmənt/

imprisonment

Meaning
the act of putting someone in prison; the state of being confined as punishment
Example
He faced imprisonment for violating the court order.
C1 adjective /ˌɪnəˈfɛnsɪv/

inoffensive

Meaning
Not likely to offend or provoke; harmless.
Example
His inoffensive remarks kept the conversation friendly.
B2 noun ˈɪn.frəˌstrʌk.tʃər

infrastructure

Meaning
The basic physical and organizational structures and facilities needed for the operation of a society or enterprise.
Example
Digital infrastructure is vital for future advancements.
C1 adjective /ɪnˈdʌktɪv/

inductive

Meaning
characterized by the inference of general laws from particular instances; reasoning from specific cases to general principles
Example
The scientist used inductive reasoning to form a hypothesis.
B2 adjective /ˌɪnɪˈfɪʃənt/

Inefficient

Meaning
not achieving maximum productivity; wasteful of time or resources
Example
The old computer system was inefficient and wasted a lot of time.
B2 noun ɪˈlɪtərəsi

illiteracy

Meaning
The inability to read and write; lack of education or knowledge in a particular area.
Example
Illiteracy often leads to poverty and unemployment.
C1 adjective /ˌɪnstənˈteɪniəs/

instantaneous

Meaning
Happening immediately, without any delay.
Example
The change in temperature was almost instantaneous.
C2 verb ɪmˈbaɪb

imbibe

Meaning
Absorb or assimilate ideas or knowledge. To drink or take in.
Example
He tried to imbibe the wisdom from his mentor.
B1 noun /ɪnˈstrʌkʃənz/

instructions

Meaning
Detailed information on how something should be done or operated.
Example
Please follow the instructions on the box.
C1 adjective /ɪmˈpjʊər/

Impure

Meaning
contaminated; not clean; mixed with foreign substances
Example
The impure water caused health problems in the village.
C1 adjective /ɪnˈtræk.tə.bəl/

intractable

Meaning
Difficult or impossible to manage, control, or solve.
Example
The conflict has become an intractable problem.
C2 verb /ɪnˈhjuːm/

inhume

Meaning
to bury a dead body in the ground
Example
They inhumed the warrior with full honors.
B2 adjective /ɪmˈpɜːrfɪkt/

imperfect

Meaning
Not perfect; having faults or flaws.
Example
The painting was beautiful despite being imperfect.
C2 noun /ˈaɪ.səˌbɑːr/

isobar

Meaning
A line on a weather map connecting points of equal atmospheric pressure.
Example
The meteorologist explained how isobars indicate wind speed and direction.
C1 noun /ˌɪnklɪˈneɪʃən/

inclination

Meaning
A natural tendency or urge to act or feel in a particular way.
Example
She has an inclination towards helping others.
C1 adjective /ˈɪnbɔːrn/

Inborn

Meaning
existing from birth; natural; inherent
Example
She has an inborn talent for music.
B2 adjective /ɪˈmætʃʊr/

Immature

Meaning
not fully developed; lacking emotional or intellectual development; childish
Example
His immature behavior during the meeting disappointed everyone.
C2 noun /ˌɪnkrɪˈdjuːləti/

incredulity

Meaning
the state of being unwilling or unable to believe something
Example
She looked at him with incredulity after hearing the strange story.
C1 noun /ˌɪn.dʒəˈnjuː.ɪ.ti/

ingenuity

Meaning
The quality of being clever, original, and inventive.
Example
His ingenuity led to groundbreaking innovations.
A2 verb /ɪmˈpruːv/

improve

Meaning
to make or become better; to enhance quality or condition
Example
Practice helps improve your skills.
C1 adjective /ɪˈmækjələt/

immaculate

Meaning
perfectly clean, neat, or free from flaws
Example
Her room was immaculate, with everything in its place.
B2 noun ɪnˈfleɪʃən

inflation

Meaning
A general increase in prices and fall in the purchasing value of money.
Example
Inflation erodes the purchasing power of consumers.
C1 adjective /ɪnˈtjuː.ɪ.tɪv/

intuitive

Meaning
Based on instinctive understanding rather than reasoning.
Example
The software has an intuitive design that makes it easy to use.
B2 adverb /ɪmˈpɔːtəntli/

importantly

Meaning
in a way that is of great significance or value
Example
Importantly, the report highlights the need for immediate action.
B1 noun /ɪnˌvɛs.tɪˈɡeɪ.ʃən/

investigation

Meaning
the process of inquiring into or examining something carefully to find the truth
Example
The investigation revealed new evidence about the fraud.
C1 adjective /ɪmˈpɑːrʃəl/

Impartial

Meaning
treating all sides fairly; unbiased; neutral
Example
A good judge must remain impartial throughout the trial.
C2 adjective /ˌɪnkɒntrəˈvɜːtəbl/

incontrovertible

Meaning
impossible to deny or dispute; unquestionable
Example
The evidence was incontrovertible and proved his innocence.