C1 adjective /ɪmˈpɛn.ɪ.trə.bəl/

impenetrable

Meaning

Impossible to pass through or enter; impossible to understand.

Example

The dense forest was nearly impenetrable.

C1 noun /ɪnˈtɛstɪn/

intestine

腸

Meaning

The part of the digestive system where food is digested and absorbed, extending from the stomach to the anus.

Example

The doctor explained how nutrients are absorbed in the small intestine.

医者は、小腸で栄養素がどのように吸収されるかを説明しました。

C1 verb /ɪnˈfɛst/

infest

侵入する

Meaning

to overrun in large numbers, especially so as to cause damage or discomfort

Example

The old house was infested with rats.

古い家はネズミで侵されていました。

C1 noun ɪˌræʃ.ənˈæl.ɪ.ti

irrationality

非合理性, 非論理性, 不合理

Meaning

The quality of being illogical or unreasonable; lack of rational thought.

Example

His decision was driven by complete irrationality.

彼の決定は完全に非合理的でした。

C1 adjective /ɪnˈvɑːlənˌtɛri/

involuntary

不随意

Meaning

done without will or conscious control

Example

He gave an involuntary shiver when he heard the loud noise.

彼は大きな音を聞いたとき、不随意に震えた。

C1 adjective /ɪnˈɛlɪdʒəbəl/

Ineligible

不適格; 無資格; 選ばれない

Meaning

not qualified or entitled to participate or be chosen; unsuitable

Example

Students with poor grades are ineligible for the scholarship program.

成績が悪い学生は奨学金プログラムに応募できません。

C1 adjective /ˌaɪdiəˈlɪstɪk/

Idealistic

理想主義的

Meaning

pursuing high principles or ideals; unrealistically optimistic

Example

She has an idealistic view of changing the world.

彼女は世界を変えるという理想主義的な見方を持っています。

C1 adjective /ˌɪn.ɪˈfɛk.tʃu.əl/

ineffectual

効果がない

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.

マネージャーの効果がないリーダーシップは、チームがモチベーションを失う原因となった。

C1 adjective /ˌɪndɪˈspjuːtəbəl/

Indisputable

議論の余地がない; 否定できない; 確定的

Meaning

impossible to deny or argue against; undeniable; certain

Example

The evidence against him was indisputable.

彼に対する証拠は議論の余地がなかった。

C1 noun /ˈɪnlɛt/

inlet

入り江

Meaning

A small arm of the sea, a lake, or a river; an opening or passage for entry.

Example

The boat entered a narrow inlet along the coast.

船は海岸沿いの狭い入り江に入った。

C1 noun /ˌɪntɪˈmeɪʃən/

intimation

示唆

Meaning

A subtle or indirect hint or suggestion.

Example

She gave no intimation of her plans.

彼女は自分の計画について何の示唆も与えなかった。

C1 noun ˌɪm.pʌlˈsɪv.ɪ.ti

impulsivity

衝動性

Meaning

The tendency to act quickly and without thought or care; lack of self-control.

Example

His impulsivity led him to make reckless choices.

彼の衝動性は、無謀な選択をさせた。

C1 noun ˌɪnfɛsˈteɪʃən

infestation

侵入, 異常に大量の昆虫や動物がある場所に存在すること

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.

キッチンにおけるアリの侵入は、即座に害虫駆除対策を講じる結果となった。

C1 adjective ˌɪdiəsɪnˈkrætɪk

idiosyncratic

奇妙で個人的な

Meaning

Relating to idiosyncrasy; peculiar or individual.

Example

His idiosyncratic behavior set him apart from his colleagues.

彼の独特な行動は彼を同僚たちから区別させた。

C1 noun /ˈɪŋ.krə.mənt/

Increment

増加

Meaning

an increase or addition, especially one of a series on a fixed scale; a regular increase in salary

Example

He received an annual increment of five percent in his salary this year.

彼は今年、自分の給料に5パーセントの年次増加を受け取った。

C1 adjective /ˈaɪərnˌklæd/

ironclad

鉄壁の

Meaning

impossible to change, break, or dispute; very strong and firm

Example

The company had an ironclad contract with its suppliers.

その会社はサプライヤーと鉄壁の契約を結んでいた。

C1 noun /aɪl/

isle

小さな島

Meaning

A small island or peninsula, often poetic or literary.

Example

They spent their honeymoon on a beautiful tropical isle.

彼らは美しい熱帯の島でハネムーンを過ごしました。

C1 noun /ˈɪnkwest/

inquest

調査

Meaning

A legal or official inquiry, especially into the cause of a death.

Example

The inquest revealed the cause of the accident.

調査は事故の原因を明らかにしました。

C1 adjective /ɪnˈvɜːs/

Inverse

逆の; 反対の

Meaning

opposite in order, nature, or effect; reversed

Example

There is an inverse relationship between price and demand.

価格と需要の間に逆の関係があります。

C1 verb ɪˈmɜːrs

immerse

浸る

Meaning

To involve oneself deeply in a particular activity or interest; to surround completely.

Example

Immerse yourself in the new language.

新しい言語に浸ってください。

C1 verb /ɪnˈfrɪndʒ/

infringe

侵害する

Meaning

To actively break the terms of a law, agreement, or right.

Example

Copying this software without permission will infringe copyright laws.

許可なくこのソフトウェアをコピーすると著作権法を侵害することになります。

C1 adjective /ɪmˈpɑːrʃəl/

Impartial

公正; 中立的

Meaning

treating all sides fairly; unbiased; neutral

Example

A good judge must remain impartial throughout the trial.

優れた裁判官は裁判中に公正を保たなければなりません。

C1 adverb /ɪnˈvɜːrs.li/

Inversely

逆に; 反対に

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.

商品の価格は市場での入手可能性に逆に関連しています。

C1 adjective /ˈɪrɪtəbl/

irritable

Meaning

easily annoyed or made angry

Example

She became irritable after working long hours without rest.

C1 verb /ɪnˈklaɪn/

incline

傾く

Meaning

to feel willing or favorably disposed toward something; to bend or tilt

Example

She is inclined to agree with the proposal.

彼女は提案に賛成する傾向があります。

C1 adjective /ˌɪmprɪˈsaɪs/

imprecise

不正確

Meaning

Not exact or accurate; vague.

Example

His explanation was too imprecise to be helpful.

彼の説明はあまりにも不正確で役に立たなかった。

C1 adjective /ɪmˈprɒmp.tjuː/

impromptu

即興

Meaning

Done without being planned, organized, or rehearsed; spontaneous.

Example

He gave an impromptu speech at the event.

彼はイベントで即興のスピーチを行いました。

C1 noun /ɪnˈdjuːsmənt/

inducement

誘因

Meaning

something that persuades or encourages someone to do something

Example

The company offered a bonus as an inducement to employees.

会社は従業員にインセンティブとしてボーナスを提供しました。

C1 adjective /ɪnˈdʌstriəs/

industrious

勤勉な

Meaning

Hardworking and diligent in one's duties.

Example

She is an industrious student who always completes her assignments on time.

彼女は常に期限通りに課題を終わらせる勤勉な学生です。

C1 noun /ˈɪmɪnəns/

imminence

差し迫り、間近な状態

Meaning

the state of being about to happen

Example

The imminence of the storm forced people to take shelter.

嵐の差し迫りが人々を避難させることを強制した。

C1 noun /ɪnˈdaɪtmənt/

indictment

起訴状

Meaning

a formal charge or accusation of a serious crime

Example

The indictment accused the company of multiple violations.

起訴状は、会社に対する複数の違反を告発しました。

C1 noun /ɪnˈtruː.ʒən/

intrusion

不正侵入

Meaning

Unauthorized entry into a system or place without permission

Example

The company detected an intrusion in its server.

会社はサーバーに侵入を検出しました。

C1 adjective /ɪnˈedəbəl/

Inedible

食べられない

Meaning

not suitable or safe for eating; not edible

Example

The mushrooms were poisonous and completely inedible.

そのキノコは毒性があり、完全に食べられないものでした。

C1 noun /ˈɪd.i.əm/

idiom

イディオム

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.

イディオム '氷を破る' は、友好的な方法で会話を始めることを意味します。

C1 adjective /ɪnˈdiːsənt/

indecent

不品な

Meaning

not conforming to accepted standards of behavior or morality; improper or offensive

Example

He was warned for making an indecent remark during the meeting.

彼は不品な発言で注意された。

C1 verb /ˈɪnkjʊˌbeɪt/

incubate

孵化する

Meaning

to keep eggs, cells, or organisms at the right conditions for development

Example

The hen will incubate the eggs until they hatch.

そのニワトリは卵が孵化するまでインキュベートします。

C1 verb /ɪnˈsaɪt/

incite

扇動する

Meaning

to provoke; to stir up

Example

His speech incited the crowd to violence.

彼のスピーチは群衆を暴力に駆り立てた。

C1 adjective /ˌɪlɪˈdʒɪtɪmət/

illegitimate

不正

Meaning

Not authorized by law, rules, or standards; not recognized as valid.

Example

The court ruled the contract to be illegitimate.

裁判所は契約が不正であると判断しました。

C1 noun ˈɪn.fər.əns

inference

推論

Meaning

A conclusion reached on the basis of evidence and reasoning; logical deduction.

Example

Scientists make inferences based on experimental data.

科学者たちは実験データに基づいて推論を行います。

C1 adjective ɪnɪɡˈzɔːstɪbəl

inexhaustible

尽きることのない

Meaning

Unable to be used up or worn out; limitless.

Example

His inexhaustible energy allowed him to work tirelessly on his projects.

彼の尽きることのないエネルギーは、彼がプロジェクトに休むことなく取り組むことを可能にしました。

C1 adjective /ˌɪnkəʊˈhɪərənt/

incoherent

一貫性のない

Meaning

Not clear or easy to understand; lacking logical connection.

Example

His explanation was so incoherent that nobody could follow it.

彼の説明はあまりにも一貫性がなく、誰もそれを追うことができませんでした。

C1 noun /ˈɪntərˌpleɪ/

interplay

相互作用

Meaning

The way in which two or more things have an effect on each other.

Example

The interplay between culture and technology shapes modern life.

文化と技術の相互作用が現代生活を形作っています。

C1 adjective /ɪnˈvæljʊəbl/

invaluable

計り知れない価値がある

Meaning

Extremely useful or indispensable.

Example

Her advice proved invaluable to my success.

彼女の助言は私の成功にとって非常に貴重でした。

C1 adjective /ɪmˈpɜːrviəs/

impervious

透過しない

Meaning

Not allowing fluid to pass through; unable to be affected by something.

Example

The jacket is impervious to rain.

ジャケットは雨に透過しません。

C1 adjective /ˌɪnɑːrˈtɪkjʊlət/

inarticulate

言葉が不明瞭

Meaning

Unable to express oneself clearly or effectively in speech or writing.

Example

She became inarticulate with emotion during the speech.

彼女はスピーチ中に感情で言葉が不明瞭になった。

C1 adjective /ˈɪnfəməs/

infamous

悪名高い

Meaning

well known for some bad quality or deed

Example

The dictator was infamous for his cruelty.

その独裁者はその残虐さで悪名高かった。

C1 noun /ˌɪn.trəˈspek.ʃən/

introspection

内省

Meaning

The examination or observation of one's own mental and emotional processes; self-reflection.

Example

Through introspection, she gained insight into her emotions.

内省を通じて、彼女は自分の感情に対する深い洞察を得ました。

C1 adjective ɪn ˈfleɪ.ʃə.ner.i

inflationary

インフレ的

Meaning

Characterized by or tending to cause monetary inflation; relating to rising prices.

Example

The government took measures to control inflationary pressures.

政府はインフレ圧力を制御するために措置を講じた。

C1 adjective /ɪnˈfleɪtɪd/

inflated

膨らんだ

Meaning

excessively increased in size, value, or importance; filled with air or gas

Example

The company faced criticism for its inflated prices.

その会社は膨らんだ価格で批判を受けました。

C1 noun /ˌɪnfɪˈdɛləti/

infidelity

不倫

Meaning

the act of being unfaithful to a spouse or partner

Example

Their marriage ended due to his infidelity.

彼らの結婚は彼の不倫が原因で終わった。

C1 noun /ɪnˈɛk.wɪ.ti/

inequity

不平等

Meaning

Lack of fairness or justice; unequal distribution or treatment.

Example

Social inequity continues to be a global issue.

社会的不平等は依然としてグローバルな問題です。

C1 adjective /ɪnˈsteɪbəl/

instable

不安定な

Meaning

not stable; liable to change, collapse, or fail; lacking firmness or reliability

Example

The instable political situation worried foreign investors.

不安定な政治状況が外国の投資家を心配させた。

C1 adjective /ɪˈluː.sɪv/

Illusive

幻想的な; 存在しているように見えるが実際には存在しない; 騙すような

Meaning

deceptive; appearing to exist but not real; misleading

Example

The promise of easy money proved to be illusive and misleading.

簡単なお金の約束は幻想的であり、誤解を招くものでした。

C1 noun /aɪˈtɪnərɛri/

itinerary

旅程

Meaning

A planned route or schedule of a journey or trip.

Example

The travel agent gave us a detailed itinerary for our vacation.

旅行代理店は私たちの休暇のために詳細な旅程を提供してくれました。

C1 noun /ɪˈmiːdiəsi/

immediacy

即時性, 緊迫感

Meaning

The quality of bringing one into direct and instant involvement with something, giving rise to a sense of urgency or excitement.

Example

The immediacy of digital communication has reshaped business operations.

デジタルコミュニケーションの即時性は、ビジネスの運営方法を変えました。

C1 adjective /ɪˈrɛvəkəbl/

irrevocable

取り消し不可能

Meaning

Not able to be revoked, changed, or undone.

Example

She made an irrevocable decision to leave the company.

彼女は会社を辞めるという取り消し不可能な決定を下した。

C1 noun /ˌɪnækˈtɪvɪti/

inactivity

不活動

Meaning

the state of not being active physically or mentally; lack of action

Example

Prolonged inactivity can negatively affect both physical and mental health.

長期間の不活動は身体的および精神的健康に悪影響を与えます。

C1 adjective /ɪˈniː.bri.eɪ.tɪd/

inebriated

酔っ払った

Meaning

under the influence of alcohol; drunk

Example

He stumbled into the room completely inebriated.

彼は完全に酔っ払って部屋に入ってきた。

C1 adjective /ɪmˈpæsɪv/

impassive

無表情

Meaning

Not showing or feeling emotion; expressionless.

Example

Despite the shocking news, she remained impassive.

衝撃的なニュースにもかかわらず、彼女は無表情のままでした。

C1 adjective /ɪmˈpɜːrsənl/

impersonal

無個性

Meaning

not influenced by, showing, or involving personal feelings; lacking human warmth or emotion

Example

The letter was written in a very impersonal style.

その手紙は非常に無個性的なスタイルで書かれていました。

C1 adjective /ɪˈmækjələt/

immaculate

完璧

Meaning

perfectly clean, neat, or free from flaws

Example

Her room was immaculate, with everything in its place.

彼女の部屋は完璧で、すべてが所定の位置にありました。

C1 noun /ɪnˈdɪf.ər.əns/

Indifference

無関心; 無関心さ; アパシー

Meaning

lack of interest, concern, or sympathy; the state of not caring about something

Example

His indifference to his studies resulted in poor grades throughout the semester.

彼の学業に対する無関心さが、学期中ずっと悪い成績をもたらした。

C1 noun /ɪnˈsaɪtmənt/

incitement

扇動

Meaning

the action of provoking unlawful or violent behavior

Example

He was arrested for incitement to riot.

彼は暴動を扇動した罪で逮捕された。

C1 adjective /ɪnˈkwɪzɪtɪv/

inquisitive

好奇心旺盛な

Meaning

Curious or eager to learn and ask questions.

Example

The inquisitive child asked endless questions about the stars.

好奇心旺盛な子供は星について無限に質問をしました。

C1 adjective ˌɪn.krəˈmen.təl

incremental

増分的

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.

増分的な変化は持続可能性を確保します。

C1 adjective /ˈɪnərmoʊst/

Innermost

最も深い; 最も個人的な

Meaning

most private and secret; deepest; most personal

Example

She shared her innermost feelings with her closest friend.

彼女は最も深い感情を最も親しい友人と共有しました。

C1 adjective /ˌɪn.səbˈstæn.ʃəl/

insubstantial

不十分な

Meaning

Lacking strength, substance, or solidity.

Example

The evidence provided was insubstantial and unconvincing.

提供された証拠は不十分で説得力がなかった。

C1 noun /ˈɪn.floʊ/

inflow

流入

Meaning

The movement of things such as money, people, or water into a place.

Example

The inflow of tourists boosted the local economy.

観光客の流入が地域経済を活性化させた。

C1 adjective /ɪmˈpoʊzɪŋ/

imposing

威圧的な

Meaning

having an appearance that is grand, impressive, or commanding

Example

The castle is an imposing structure overlooking the valley.

その城は谷を見下ろす威圧的な構造です。

C1 adjective /ɪnˈflæməbəl/

Inflammable

可燃; 発火性

Meaning

easily set on fire; flammable; combustible

Example

The inflammable material caught fire quickly.

その可燃性材料はすぐに火をつけました。

C1 adjective /ɪnˈdʌldʒənt/

indulgent

寛容な

Meaning

Having a tendency to be overly generous or lenient with someone.

Example

The indulgent mother allowed her child to stay up late.

寛容な母は子供を遅くまで起きていることを許しました。

C1 noun /ˌɪnsəˈfɪʃənsi/

insufficiency

不足

Meaning

The state of not being enough or not being adequate.

Example

The project failed due to the insufficiency of funds.

プロジェクトは資金不足のため失敗しました。

C1 noun /ˈɪtʃ.i.nəs/

itchiness

かゆみ

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.

目のかゆみはしばしば擦る原因となります。

C1 noun ˌɪn.tuˈɪʃ.ən

intuition

直感

Meaning

The ability to understand something immediately, without the need for conscious reasoning.

Example

Her intuition told her something was wrong.

彼女の直感は何かが間違っていると言った。

C1 verb /ɪnˈstɪl/

instill

植え付ける

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.

親は子供に良い価値観を植え付けようとしています。

C1 verb /ɪnˈsɪnjueɪt/

insinuate

Meaning

To suggest or hint something indirectly and often unpleasantly.

Example

He insinuated that she had lied about her qualifications.

C1 adjective /ˌɪnsərˈmaʊntəbl/

insurmountable

克服不可能

Meaning

Too great to be overcome.

Example

The explorers faced insurmountable odds in the desert.

探検者たちは砂漠で克服不可能な障害に直面した。

C1 noun /ˈɪn.tə.mə.si/

Intimacy

親密さ; 親しみ

Meaning

close familiarity or friendship; closeness; a private cozy atmosphere

Example

The couple valued the emotional intimacy they shared more than material possessions.

そのカップルは物質的な所有物よりも、共有した感情的な親密さを大切にしていました。

C1 noun /ɪnˈvɜːrʒən/

inversion

逆転

Meaning

A reversal of the normal order, position, or relationship.

Example

In poetry, inversion is often used to create emphasis.

詩では、逆転は強調を作るためによく使われます。

C1 adjective /ˌɪndɪˈvɪzəbl/

indivisible

Meaning

Not able to be divided or separated.

Example

The country's unity was indivisible despite differences.

C1 noun /ˌɪməˈrælɪti/

immorality

不道徳

Meaning

the quality of being immoral; behavior that violates accepted moral standards

Example

The community condemned the immorality of the corrupt officials.

地域社会は腐敗した役人の不道徳を非難した。

C1 adjective /ɪˈmeʒərəbəl/

Immeasurable

計り知れない

Meaning

too large or extensive to measure; boundless

Example

The immeasurable love of a mother knows no bounds.

母の計り知れない愛には限界がない。

C1 verb /ɪmˈpɜːrsəneɪt/

impersonate

偽る

Meaning

to pretend to be another person in order to entertain or deceive

Example

He was arrested for trying to impersonate a police officer.

彼は警察官を装おうとしたため逮捕されました。

C1 noun /ˈɪŋklɪŋ/

inkling

予感

Meaning

A slight idea, hint, or suspicion about something.

Example

She had an inkling that he was planning a surprise.

彼女は彼がサプライズを計画しているという予感を持っていた。

C1 noun /ˌɪndɪˈdʒɛstʃən/

indigestion

Meaning

Discomfort or pain in the stomach associated with difficulty in digesting food.

Example

He avoided spicy food because it often gave him indigestion.

C1 noun /ɪnˈkɜːrʒən/

incursion

侵入

Meaning

A sudden attack or invasion into a place or territory.

Example

The army repelled the enemy incursion at the border.

軍隊は国境で敵の侵入を撃退した。

C1 noun /ɪnˈsɜːrdʒənt/

insurgent

反乱者

Meaning

A person who rises in revolt against authority or government.

Example

The army arrested several insurgents after the attack.

軍隊は攻撃後、数人の反乱者を逮捕した。

C1 verb /ɪˈmɔːrtəlaɪz/

immortalize

不朽の

Meaning

to preserve the memory of someone or something forever

Example

The statue was built to immortalize the hero’s sacrifice.

その像は、英雄の犠牲を永遠にするために建てられました。

C1 noun /ˌɪnsɪɡˈnɪfɪkəns/

insignificance

重要でないこと

Meaning

The quality of being unimportant or trivial.

Example

He felt a sense of insignificance in the vast universe.

彼は広大な宇宙で重要でないことを感じました。

C1 verb /ˈɪmplɪˌkeɪt/

implicate

関与する

Meaning

To show someone’s involvement in a crime or wrongdoing.

Example

The evidence implicated several officials in the scandal.

証拠はスキャンダルに関与した何人かの職員を示した。

C1 noun /ˈɪnflʌks/

influx

流入

Meaning

A large arrival or flow of people or things.

Example

The city experienced an influx of tourists during the festival.

その都市は祭りの期間中に観光客の流入を経験しました。

C1 noun /ˌɪnɪkˈspɪəriəns/

inexperience

未経験

Meaning

Lack of knowledge or skill in a particular activity or field.

Example

His inexperience in handling negotiations was evident.

交渉における彼の未経験は明らかでした。

C1 noun ɪnˈflɛk.ʃən

inflection

イントネーション

Meaning

The change in pitch or tone of voice when speaking for emphasis.

Example

His inflection kept the audience engaged.

彼のイントネーションは観客を引きつけた。

C1 adjective /ˌɪndɪˈstrʌktəbl/

indestructible

壊れない

Meaning

Impossible to destroy or break.

Example

The superhero's shield was said to be indestructible.

スーパーヒーローの盾は壊れないと言われていました。

C1 noun /ˈɪrɪtənt/

irritant

刺激物

Meaning

something that causes irritation or discomfort

Example

Dust is a common irritant for people with allergies.

ほこりはアレルギーを持つ人々にとって一般的な刺激物です。

C1 noun /ˌɪntəkəˈnɛktɪvɪti/

interconnectivity

相互接続性

Meaning

The state of being interconnected or the degree of connectivity between components

Example

The rise of interconnectivity has transformed global communication.

インターコネクティビティの発展は、世界中のコミュニケーションを変革しました。

C1 noun /ɪnˈækjʊrəsi/

inaccuracy

不正確さ

Meaning

lack of accuracy or precision; an incorrect or wrong detail

Example

The report contained several factual inaccuracies.

その報告書にはいくつかの不正確さがあった。

C1 adjective /ɪnˈhɛrənt/

inherent

固有の

Meaning

Existing in something as a natural, permanent, or essential quality.

Example

There are inherent risks in extreme sports.

エクストリームスポーツには固有のリスクが存在する。

C1 adjective /ˌɪnɔːrˈɡænɪk/

inorganic

無機の

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.

無機化合物は化学の基本です。

C1 verb /ˌɪn.trəˈspekt/

introspect

内省する

Meaning

To examine one's own thoughts, feelings, or mental state.

Example

He often introspects before making important decisions.

彼は重要な決定を下す前にしばしば自己分析をします。

C1 adjective /ɪnˈsɪstənt/

insistent

執拗な

Meaning

demanding something firmly and refusing to accept no

Example

The child was insistent on getting a new toy.

その子供は新しいおもちゃを手に入れることに執拗だった。

C1 adjective ɪˈluː.sər.i

illusory

幻の

Meaning

Based on illusion; not real although seeming to be.

Example

His sense of security was entirely illusory.

彼の安全感は完全に幻のものだった。

C1 adjective /aɪˈdɪlɪk/

idyllic

田園詩のように美しい

Meaning

Like an idyll; extremely happy, peaceful, or picturesque.

Example

They enjoyed an idyllic vacation by the sea.

彼らは海辺で田園詩のような休暇を楽しみました。

C1 adjective /ˌɪnəˈfɛnsɪv/

inoffensive

無害な

Meaning

Not likely to offend or provoke; harmless.

Example

His inoffensive remarks kept the conversation friendly.

彼の無害なコメントは会話を友好的に保ちました。

C1 adjective ˌɪn.təˈmɪt.ənt

intermittent

断続的

Meaning

Happening irregularly, not continuously.

Example

The rain was intermittent throughout the day.

雨は一日中断続的でした。

C1 adjective /ˌɪnkɒmprɪˈhɛnsəbl/

incomprehensible

理解不能

Meaning

Impossible or very difficult to understand.

Example

The professor’s lecture was so fast it became incomprehensible.

教授の講義は速すぎて理解不能になった。

C1 verb /aɪˈdiː.ə.laɪz/

idealize

理想化する

Meaning

To regard or represent something as perfect or better than it really is.

Example

Children often idealize their parents.

子供たちはしばしば親を理想化します。

C1 noun /ˌɪmɔːrˈtæləti/

immortality

不死; 永遠の命

Meaning

the state of living forever; eternal life or lasting fame beyond death

Example

Many ancient cultures believed that heroes could achieve immortality through great deeds.

多くの古代文化では、英雄が偉業によって不死を得られると信じられていた。

C1 noun ɪnˈdʌldʒəns

indulgence

嗜好

Meaning

The practice of allowing oneself to enjoy the pleasure of something.

Example

His indulgence in junk food affected his health.

彼のジャンクフードへの過度の嗜好は健康を害した。

C1 adjective ɪmˈpɛkəbl

impeccable

完璧な

Meaning

In accordance with the highest standards; faultless.

Example

His impeccable taste in fashion was admired by all his peers.

彼の完璧なファッションセンスは、すべての同僚に賞賛されました。

C1 adjective /ɪmˈpɜːrtɪnənt/

impertinent

無礼な

Meaning

rude and showing a lack of respect

Example

It was impertinent of him to question the manager's decision.

マネージャーの決定に疑問を呈するのは無礼でした。

C1 adjective /ɪnˈtændʒəbl/

intangible

無形の

Meaning

Unable to be touched or grasped; not having a physical presence.

Example

Trust is an intangible quality in relationships.

信頼は関係において無形の特質です。

C1 adjective /ɪnˈtɛlɪdʒəbl/

intelligible

Meaning

Able to be understood; clear enough to be comprehended.

Example

Her speech was barely intelligible over the noise.

C1 adjective /ˌɪnˌkɒnsɪˈkwɛnʃəl/

inconsequential

重要でない

Meaning

Not important or significant; too small to matter.

Example

The mistake was minor and inconsequential.

その間違いは小さく、重要ではありませんでした。

C1 noun /ˈɪn.fən.tri/

Infantry

歩兵

Meaning

soldiers marching or fighting on foot; foot soldiers collectively

Example

The infantry advanced across the battlefield on foot.

歩兵は戦場を徒歩で進んだ。

C1 verb /ɪnˈfjuːz/

infuse

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.

C1 adverb /ˌɪn.dɪˈskrɪm.ɪ.nət.li/

Indiscriminately

無差別に

Meaning

without making careful distinctions; randomly; without discrimination

Example

The company fired employees indiscriminately without considering their performance.

会社は従業員を彼らのパフォーマンスを考慮せずに無差別に解雇しました。

C1 noun /ˌɪnkəmˈpliːtnəs/

incompleteness

不完全さ

Meaning

the state of not being complete or whole; lack of necessary parts or fullness

Example

The incompleteness of the report caused delays in the project.

レポートの不完全さがプロジェクトの遅れを引き起こした。

C1 adjective /ˌɪrɪˈspɛktɪv/

Irrespective

無視して; 問わず

Meaning

without taking something into account; regardless of

Example

All students will be treated equally, irrespective of their background.

すべての学生は、背景に関係なく平等に扱われます。

C1 adjective /ˈɪnsjələr/

insular

狭い心の、島に関連する

Meaning

Narrow-minded, isolated, or relating to an island.

Example

The community was criticized for its insular attitudes toward outsiders.

そのコミュニティは外部の人々に対する狭量な態度で批判されました。

C1 noun /ɪmˈprɪzənmənt/

imprisonment

投獄

Meaning

the act of putting someone in prison; the state of being confined as punishment

Example

He faced imprisonment for violating the court order.

彼は裁判所の命令に違反して投獄に直面した。