infantile
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C2 adjective /ˈɪnfəntaɪl/

infantile

幼稚な
Meaning
characteristic of an infant; childish
Example
His infantile behavior embarrassed everyone at the meeting.
彼の幼稚な行動は会議でみんなを困らせた。
C2 adjective /ˌɪnkænˈdɛsənt/

incandescent

白熱
Meaning
emitting light as a result of being heated; extremely bright or passionate
Example
The incandescent lamp lit up the entire hall.
白熱灯はホール全体を照らしました。
C2 noun /ɪnˈtɛɡ.jʊ.mənt/

integument

外皮
Meaning
A natural outer covering, such as skin, shell, or rind.
Example
The snake sheds its integument as it grows.
ヘビは成長するにつれて外皮を脱ぎます。
C2 noun /ˈaɪ.ərn.wʊd/

Ironwood

アイアンウッド
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.
アイアンウッドの木は小さな白い花を咲かせます。
C2 adjective /ɪnˈsɛnʃənt/

insentient

無感覚の
Meaning
Lacking perception, consciousness, or sensation.
Example
The rock is an insentient object with no awareness.
岩は意識のない無感覚の物体です。
C2 noun /ɪmp/

imp

小さないたずら好きな悪魔
Meaning
a small mischievous devil or sprite; a playful troublemaker
Example
The child was acting like a little imp, hiding his toys everywhere.
その子供は小さなインプのように振る舞い、どこにでもおもちゃを隠していました。
C2 adjective /ˌɪnkɔːrˈpɔːriəl/

incorporeal

無形
Meaning
lacking a physical body; not composed of matter; intangible
Example
Ghosts are often described as incorporeal beings.
ゴーストはしばしば無形の存在として描かれます。
C2 adjective /ˌɪntərˈlɒkjətəri/

interlocutory

仮の
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.
裁判官は聴聞会まで現状を維持するために仮の命令を出しました。
C2 adjective /ɪnˈvaɪələbl/

inviolable

侵害できない
Meaning
never to be broken, dishonored, or violated
Example
Human rights are considered inviolable in modern democracies.
人権は現代の民主主義において侵害できないと見なされています。
C2 noun /ɪnˈsɪɡniə/

insignia

徽章
Meaning
A badge or symbol that shows rank, position, or membership.
Example
The soldier proudly wore the insignia of his regiment.
兵士は誇らしげに自分の連隊の徽章を身に着けていました。
C2 noun /ɪnˈfrækʃən/

infraction

違反
Meaning
A violation or breach of a rule, law, or agreement.
Example
The student was punished for a minor infraction of the school rules.
学生は学校の規則の軽微な違反で罰せられました。
C2 adjective /ɪˈmɪsəbl/

immiscible

不混和
Meaning
Describes liquids that do not mix together.
Example
Oil and water are immiscible liquids.
油と水は不混和の液体です。
C2 noun /ˌɪntərpəˈzɪʃən/

interposition

介入
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.
マネージャーの介入は、激しい議論がエスカレートするのを防ぎました。
C2 adjective ˌɪm.pəˈtɜː.bə.bəl

imperturbable

冷静沈着
Meaning
Unable to be upset or excited; not easily disturbed.
Example
His imperturbable nature made him a great leader.
彼の冷静沈着な性格は、彼を偉大なリーダーにした。
C2 verb /ˈɪməleɪt/

immolate

犠牲にする/焼死させる
Meaning
To kill or sacrifice, especially by burning.
Example
The protesters threatened to immolate themselves in front of the building.
抗議者たちは建物の前で自ら火にくべると脅した。
C2 noun /ˌɪmpəˈtjuːəsəti/

impetuosity

衝動性
Meaning
The quality of being rash or impulsive.
Example
His impetuosity often got him into trouble.
彼の衝動性はしばしば彼を問題に巻き込んだ。
C2 adjective /ɪnˈsɛptɪv/

inceptive

初期の
Meaning
Relating to or marking the beginning or initial stage of something.
Example
The inceptive phase of the project was marked by enthusiastic planning.
プロジェクトの開始段階は熱心な計画で特徴づけられました。
C2 noun /ɪnˈhɪərəns/

inherence

内在性
Meaning
The state of being an essential or permanent part of something.
Example
The inherence of risk is part of every business venture.
リスクの内在性はすべてのビジネス冒険の一部です。
C2 verb /ɪnˈhjuːm/

inhume

埋葬する
Meaning
to bury a dead body in the ground
Example
They inhumed the warrior with full honors.
彼らは戦士を完全な名誉を持って埋葬しました。
C2 noun /ˌɪntərˈsɛʃən/

intercession

仲介
Meaning
the act of intervening or pleading on behalf of another person
Example
The prisoner was released due to the intercession of influential leaders.
囚人は影響力のあるリーダーたちの仲介で釈放されました。
C2 adjective /ˌɪndaɪˈdʒestəbəl/

Indigestible

消化不良な; 消化しにくい
Meaning
difficult or impossible to digest; hard to process in the stomach
Example
The old bread became hard and indigestible.
古いパンは硬くなり、消化不良になった。
C2 adjective /ɪnˈkɑːdʒɪtənt/

incogitant

無思慮な
Meaning
Lacking thought; inconsiderate or thoughtless.
Example
It was incogitant of him to make such a rude comment.
彼がそんな失礼なコメントをするのは無思慮なことでした。
C2 noun /ˈaɪ.səˌbɑːr/

isobar

等圧線
Meaning
A line on a weather map connecting points of equal atmospheric pressure.
Example
The meteorologist explained how isobars indicate wind speed and direction.
気象学者は、等圧線が風速と風向きを示す方法を説明しました。
C2 noun /ɪmˌpɜːrtərbəˈbɪləti/

imperturbability

不動心
Meaning
The quality of being calm and not easily disturbed or upset.
Example
Her imperturbability during the crisis impressed everyone.
危機の際に彼女の不動心は皆に印象を与えました。
C2 verb /ɪnˈsteɪt/

instate

任命する
Meaning
To set up in position, office, or authority.
Example
The board decided to instate her as the new director.
取締役会は彼女を新しいディレクターにインステイトすることを決定しました。
C2 adjective /ɪnhɑːrˈmoʊniəs/

Inharmonious

不協和音
Meaning
lacking harmony; discordant in sound; not in tune
Example
The inharmonious sounds from the broken piano made everyone cover their ears.
壊れたピアノからの不協和音がみんなを耳をふさがせました。
C2 adjective /ɪˈrɛzəluːt/

irresolute

優柔不断
Meaning
uncertain or indecisive; lacking determination
Example
He stood irresolute at the crossroads, unsure which path to take.
彼は交差点で優柔不断に立ち、どの道を取るべきか決められなかった。
C2 verb ˈɪnʌndeɪt

inundate

洪水で満たす、処理すべき事柄や人々で誰かまたは何かを圧倒する
Meaning
To flood; overwhelm someone or something with things or people to be dealt with
Example
The company was inundated with requests after the advertisement.
広告の後、会社はリクエストで圧倒されました。
C2 verb /ɪmˈpjuːt/

impute

帰する
Meaning
to attribute a fault or responsibility to someone
Example
They imputed the company's success to good leadership.
彼らは会社の成功を良いリーダーシップに帰属させた。
C2 noun /ˌɪn.təˈvɛn.ʃə.nɪ.zəm/

interventionism

介入主義
Meaning
Government policy of active involvement in economic affairs.
Example
The central bank's interventionism helped stabilize inflation.
中央銀行の介入主義はインフレの安定に役立った。
C2 adjective /ˌɪnsəˈluːbriəs/

insalubrious

不健康
Meaning
Unhealthy or not conducive to well-being.
Example
They moved out of the insalubrious neighborhood for the sake of their health.
彼らは健康のために不健康な地域から引っ越しました
C2 noun /ˈɪɡ.nəˌmɪn.i/

ignominy

恥辱
Meaning
Public shame, disgrace, or dishonor.
Example
He lived the rest of his life in ignominy after the scandal.
スキャンダル後、彼は生涯を恥辱の中で過ごした。
C2 adjective /ɪˈmɒdərət/

immoderate

過度な
Meaning
excessive; beyond reasonable limits
Example
He has an immoderate love for sweets.
彼はお菓子に対して過度の愛情を持っています。
C2 noun /ɪnˈfriːkwəns/

infrequence

稀少性
Meaning
The state of occurring rarely or at long intervals.
Example
The infrequence of their meetings made it hard to maintain close ties.
彼らの会議の稀少性は、親密な関係を維持するのを難しくしていました。
C2 adjective /ɪmˌpɜːrˈsweɪdəbl/

impersuadable

説得できない
Meaning
not able to be convinced or persuaded
Example
She remained impersuadable despite all our arguments.
彼女はすべての議論にもかかわらず説得できなかった。
C2 adjective /aɪˈdɒlətrəs/

idolatrous

偶像崇拝者
Meaning
Excessively admiring or worshipping someone or something as an idol.
Example
The king was criticized for his idolatrous devotion to wealth.
王は富に対する偶像崇拝的な献身で批判されました。
C2 adjective /ɪˈræsɪbl/

irascible

怒りっぽい
Meaning
Easily angered; quick-tempered.
Example
His irascible nature often got him into trouble.
彼の怒りっぽい性格はよくトラブルを引き起こしていた。
C2 adverb /ˌɪnsəʊˈmʌtʃ/

insomuch

これほど
Meaning
to such an extent
Example
He was insomuch tired that he could hardly stand.
彼はあまりにも疲れていて、ほとんど立つことができませんでした。
C2 adjective /ˌɪntəˈrɒɡətəri/

interrogatory

尋問的な
Meaning
expressed in the form of a question; relating to questioning
Example
The lawyer’s interrogatory tone made the witness uncomfortable.
弁護士の尋問的な口調は証人を不快にさせました。
C2 noun /ɪnˈtɜːrstɪs/

interstice

隙間
Meaning
a small space that lies between things
Example
Light filtered through the narrow interstices of the wall.
光は壁の狭い隙間を通して漏れた。
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.
C2 adjective /ˌɪrɪˈtriːvəbl/

irretrievable

回復不可能
Meaning
impossible to recover or regain
Example
The documents were lost in an irretrievable way after the fire.
火事の後、文書は回復不可能な方法で失われました。
C2 adjective /ˌɪrɪˈfrændʒɪbəl/

irrefrangible

侵害できない
Meaning
Not to be broken, violated, or infringed
Example
The constitution guarantees certain irrefrangible rights to every citizen.
憲法はすべての市民にいくつかの侵害できない権利を保証します。
C2 noun /ɪmˈpaɪ.ə.ti/

Impiety

不敬
Meaning
lack of piety or reverence, especially for a god; disrespect or irreverence toward religious matters
Example
His impiety shocked the religious community when he mocked their sacred ceremonies.
彼の不敬は、彼が彼らの神聖な儀式を嘲笑したとき、宗教コミュニティを驚かせました。
C2 noun /ɪnˈtræn.sɪ.dʒəns/

intransigence

不屈
Meaning
Refusal to change one's views or to agree about something.
Example
The negotiations failed due to the intransigence of both parties.
両者の不屈の姿勢のために交渉は失敗した。
C2 adjective /ɪnˈsɪpɪd/

insipid

味気ない
Meaning
lacking flavor, interest, or excitement; dull
Example
The soup was insipid and needed more seasoning.
スープは味気なく、もっと調味料が必要でした。
C2 adjective ˌɪn.ɪ.fɪˈkeɪ.ʃəs

inefficacious

効果がない
Meaning
Not producing any or the desired effect; ineffective.
Example
The treatment was inefficacious in curing the disease.
その治療法は病気の治癒に効果がありませんでした。
C2 adjective /ɪmˈpɔːrtʃənət/

importunate

しつこい
Meaning
Persistent to the point of annoyance or intrusion
Example
The importunate salesman kept calling despite repeated refusals.
しつこい販売員は、繰り返し拒否されても電話をかけ続けました。
C2 verb ˈɪn.kʌl.keɪt

inculcate

教え込む
Meaning
Instill an attitude, idea, or habit by persistent instruction; to teach and impress by frequent repetitions.
Example
Parents should inculcate good values in their children.
親は子供たちに良い価値観を教え込むべきだ。
C2 adjective /ˌɪrɪˈlɪdʒəs/

irreligious

無宗教
Meaning
Indifferent or hostile to religion
Example
Some people in the community consider him irreligious because he never attends religious services.
コミュニティの中で、彼は宗教的なサービスに一度も参加しないため、無宗教だと考えられています。
C2 adjective /ɪnˈkoʊətɪv/

inchoative

初期の
Meaning
relating to the beginning of something; in an initial stage
Example
The poet used inchoative expressions to depict the dawn of creation.
詩人は創造の夜明けを描くために初期の表現を使いました。
C2 verb /ɪmˈbruː/

imbrue

汚す
Meaning
To stain, especially with blood.
Example
His hands were imbrued with blood after the battle.
戦いの後、彼の手は血で汚れていた。
C2 adjective /ɪˈnɪmɪkəl/

inimical

敵対的 / 不利な
Meaning
tending to obstruct or harm; unfriendly or hostile
Example
The policy was inimical to the country's economic growth.
その政策は国の経済成長に不利だった。
C2 adjective /ˌɪrɪˈdjuːsəbl/

irreducible

不可約
Meaning
impossible to reduce or simplify further
Example
The fraction 3/7 is irreducible.
分数 3/7 は不可約です。
C2 noun /ˌɪrɪˈdɛsəns/

iridescence

虹色の輝き
Meaning
a play of lustrous, changing colors like those of a rainbow
Example
The butterfly's wings shimmered with iridescence.
蝶の羽は虹色の輝きで輝いていました。
C2 noun /ˈɪrɪɡənt/

irrigant

灌漑液
Meaning
A liquid used for irrigation, especially in medical or agricultural contexts.
Example
The doctor used a sterile irrigant during the procedure.
医師は手術中に無菌の灌漑液を使用しました。
C2 adjective /ˌaɪ.kə.nəˈklæs.tɪk/

iconoclastic

確立された信念、伝統、または価値観に対して攻撃的または拒絶的な特徴
Meaning
Characterized by attacking or rejecting cherished beliefs, traditions, or established values.
Example
Her iconoclastic views challenged the conventional wisdom of the industry.
彼女のアイコノクラスティックな見解は業界の従来の知恵に挑戦した。
C2 adjective /ɪnˈsɪpiənt/

incipient

初期の
Meaning
in an initial stage; beginning to develop
Example
The incipient storm made the sky turn dark and heavy.
初期の嵐が空を暗く重くさせた。
C2 noun /ɪmˌprɒb.əˈbɪl.ə.ti/

Improbability

不確実性
Meaning
the quality or state of being improbable; unlikely to be true or to happen
Example
The improbability of winning the lottery twice didn't stop her from buying tickets.
ロトで二回連続で当選する可能性の低さは、彼女がチケットを買うのを止めませんでした。
C2 adjective /ɪnˈkoʊ.ɪt/ or /ɪnˈkoʊ.eɪt/

inchoate

未完成
Meaning
Just begun and not fully formed; rudimentary.
Example
His inchoate ideas needed more research to be developed.
彼の未完成のアイデアは、さらに開発するためにもっと研究が必要だった。
C2 adjective /ˌɪmpəˈmɪsəbl/

impermissible

許可されていない
Meaning
Not permitted or allowed.
Example
Such behavior is impermissible in the workplace.
そのような行動は職場では許可されていません。
C2 verb /ˌɪn.trəˈmɪt/

intromit

挿入する
Meaning
To insert or introduce something into a place or body.
Example
The doctor carefully intromitted the instrument into the wound.
医者は慎重に器具を傷口に挿入しました。
C2 adjective /ɪnˈɡlɔːriəs/

inglorious

不名誉な
Meaning
Causing shame or disgrace; not bringing honor or glory.
Example
The army suffered an inglorious defeat.
軍隊は不名誉な敗北を喫した。
C2 noun /ˈɪsməs/ or /ˈɪsθməs/

isthmus

地峡
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.
パナマ運河はパナマの地峡を通ります。
C2 adjective /ˌɪm.pəˈfɛk.tə.bəl/

imperfectible

インパーフェクティブル
Meaning
Incapable of being made perfect or complete.
Example
Some human qualities are considered imperfectible.
いくつかの人間の資質は、完璧にはならないと見なされます。
C2 adjective /ɪmˈpɒndərəbl̩/

imponderable

計り知れない
Meaning
Something difficult or impossible to estimate, assess, or understand
Example
The outcome of the election depends on many imponderable factors.
選挙の結果は、多くの計り知れない要因に依存しています。
C2 adverb /ˌɪnəzˈmʌtʃ/

inasmuch

〜という点で
Meaning
To the extent that; considering that.
Example
Inasmuch as you are their teacher, you should guide them carefully.
あなたが彼らの教師である限り、彼らを慎重に指導するべきです。
C2 adjective /ˈɪnˌbrɛd/

inbred

生まれつき
Meaning
existing naturally in a person or animal; also related to reproduction within a limited community
Example
He has an inbred sense of loyalty.
彼には生まれつきの忠誠心があります。
C2 noun /ˈɪd.i.ə.si/

Idiocy

愚かさ
Meaning
extremely stupid behavior or actions; foolishness
Example
The decision to ignore safety protocols was pure idiocy that endangered everyone.
安全プロトコルを無視する決定は、すべての人を危険にさらす純粋な愚かさでした。
C2 noun /ɪnˈdɛntʃər/

indenture

Meaning
A formal legal agreement, contract, or document, often relating to work or service.
Example
In the 18th century, many workers came under indenture to work overseas.
C2 noun /ˈɪrɪtənsi/

irritancy

苛立ち
Meaning
the quality or state of causing irritation; legal or formal invalidation
Example
The constant noise became an irritancy to the neighbors.
絶え間ない騒音は隣人にとって苛立ちの原因となりました。
C2 verb /ɪnˈveɪɡəl/

inveigle

誘惑する
Meaning
To persuade someone to do something by deception or flattery.
Example
She inveigled him into signing the contract.
彼女は彼に契約書に署名させた。
C2 verb /ɪnˈɡrɑːft/

ingraft

根付ける
Meaning
To implant or fix deeply, often used in the sense of grafting an idea or quality.
Example
The teacher tried to ingraft good manners in the students.
先生は生徒たちに良いマナーを根付かせようとした。
C2 verb /ˌɪmpɔːrˈtuːn/

importune

しつこく頼む
Meaning
To ask someone persistently or pressingly for something
Example
The child importuned his mother for a new toy.
その子供は新しいおもちゃを欲しがって母親にしつこく頼んだ。
C2 verb /ˈɪndjʊˌreɪt/

indurate

硬化する
Meaning
To harden or make something physically or emotionally tough.
Example
Years of hardship indurated his spirit.
長年の困難が彼の精神を鍛えました。
C2 noun /ˌɪkθiˈɒlədʒi/

ichthyology

魚類学
Meaning
The branch of zoology that deals with fish.
Example
He pursued a degree in ichthyology at the university.
彼は大学で魚類学の学位を取得した。
C2 adjective /ˌɪɡ.nəˈmɪn.i.əs/

ignominious

不名誉な
Meaning
Marked by shame, disgrace, or humiliation.
Example
The team suffered an ignominious defeat in the finals.
チームは決勝で不名誉な敗北を喫した。
C2 noun /ɪnˌtɜːrpəˈleɪʃən/

interpolation

補間
Meaning
The act of inserting something into a text or estimating values within a sequence of data.
Example
The scientist used interpolation to predict the missing data points.
科学者は欠落したデータポイントを予測するために補間を使用しました。
C2 conjunction /ˌɪnəzˈmʌtʃ æz/

inasmuch-as

なぜなら
Meaning
Because; since.
Example
He cannot attend, inasmuch as he is unwell.
彼は出席できません、なぜなら彼は病気だからです。
C2 adjective /aɪˈtɪnərənt/

itinerant

旅する
Meaning
Traveling from place to place, especially for work or duty.
Example
The itinerant teacher moved from village to village to educate children.
その旅する教師は村から村へと移動して子供たちに教育をしていました。
C2 verb /ɪnˈsɪnəˌreɪt/

incinerate

焼却する
Meaning
to burn something completely until it is reduced to ashes
Example
The city decided to incinerate the medical waste for safety.
その都市は安全のために医療廃棄物を焼却することを決定しました。
C2 verb /ɪnˈveɪ/

inveigh

激しく批判する
Meaning
To speak or write about something with great hostility and criticism.
Example
He inveighed against the corruption in government.
彼は政府の腐敗に対して激しく批判した。
C2 adjective /ˌaɪsəʊˈθɜːrməl/

isothermal

等温
Meaning
Having or maintaining equal or constant temperature.
Example
The experiment was conducted under isothermal conditions.
実験は等温条件で行われました。
C2 noun (compound/erroneous entry) /ɪnˈɛksərəbl ɑːrmi/

inexorableinexorablearmy

止められない軍隊
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.
反乱軍は自分たちの砦に近づいてくる止められない軍隊を恐れていた。
C2 adjective /ɪˈmɒdɪst/

immodest

傲慢 / 不適切
Meaning
lacking humility or decency; excessively proud or improper
Example
His immodest remarks offended the audience.
彼の傲慢な発言は観客を不快にさせた。
C2 noun /ˌɪmprəˈpraɪəti/

impropriety

不正行為
Meaning
Failure to observe standards of honesty or modesty; improper behavior.
Example
The politician was accused of financial impropriety.
その政治家は財政的不正行為で告発されました。
C2 adjective /ˌɪməˈmɔːriəl/

immemorial

不朽の
Meaning
Extending back beyond memory or record; ancient.
Example
The tradition has been followed since time immemorial.
その伝統は不朽の時代から受け継がれてきた。
C2 verb /ɪnˈdʒɛst/

ingest

摂取する
Meaning
To take food, drink, or another substance into the body, usually by swallowing.
Example
The patient must ingest the medicine with water.
患者は水と一緒に薬を摂取する必要があります。
C2 adjective /ɪnˈɛstɪməbl/

inestimable

計り知れない
Meaning
Too great or valuable to be measured or estimated.
Example
Her contribution to the project was of inestimable value.
プロジェクトへの彼女の貢献は計り知れない価値があった。
C2 adjective /ˈɪn.dɪ.dʒənt/

indigent

困窮
Meaning
lacking the necessities of life due to poverty; very poor
Example
The hospital offers free care to indigent patients.
病院は困窮した患者に無料でケアを提供しています。
C2 adjective /ɪnˈtɛmpərət/

intemperate

不節制な
Meaning
Lacking self-control; immoderate, especially in indulgence.
Example
The politician's intemperate remarks caused controversy.
政治家の不節制な発言は論争を引き起こした。
C2 verb /ˈɪŋkʌlpeɪt/

inculpate

非難する
Meaning
To blame or accuse someone of wrongdoing.
Example
The evidence seemed to inculpate the suspect in the crime.
証拠は容疑者を犯行に巻き込んでいるように見えた。
C2 noun /ɪmˈpjuːnɪti/

impunity

Meaning
freedom from punishment or harmful consequences for an action
Example
The dictator ruled with impunity, ignoring international laws.
C2 noun /ˈɪntəˌkrɒpɪŋ/

intercropping

間作農業
Meaning
The agricultural practice of cultivating two or more crops simultaneously in the same field to maximize land use efficiency and improve soil health.
Example
Intercropping can help improve soil fertility and pest control.
間作農業は土壌の肥沃度と害虫管理の向上に役立ちます。
C2 adjective /ˌɪnæprɪˈhɛnsəbl/

inapprehensible

理解不能
Meaning
not understandable; incomprehensible
Example
The concept was so abstract that it seemed inapprehensible to most students.
その概念は非常に抽象的で、ほとんどの学生には理解できないように思えた。
C2 adverb /ˈɪntʃmiːl/

inchmeal

少しずつ
Meaning
Gradually, little by little.
Example
The old castle fell inchmeal into ruin.
その古い城は少しずつ廃墟になった。
C2 noun /ˈɪl.i.æd/

iliad

イリアス
Meaning
An ancient Greek epic poem attributed to Homer, describing the events of the Trojan War.
Example
Students studied the Iliad to understand Greek mythology and heroism.
学生たちはイリアスを学び、ギリシャ神話と英雄主義を理解しました。
C2 adjective /ɪmˈpɑːlɪtɪk/

impolitic

無礼な
Meaning
Unwise or imprudent; not showing good judgment.
Example
It would be impolitic to criticize them openly.
彼らを公然と批判するのは無礼だろう。
C2 noun /ɪnˈvaɪtər/

invitor

招待者
Meaning
a person who invites someone to an event, meeting, or place
Example
The invitor greeted all the guests warmly at the entrance.
招待者は入口で客を温かく迎えた。
C2 verb /ɪˈreɪdieɪt/

irradiate

照射する
Meaning
to shine light on something; to expose to radiation; to illuminate or brighten
Example
The scientist used a lamp to irradiate the sample.
科学者はランプを使ってサンプルを照射しました。
C2 noun /ˌɪntərˈsɛsər/

intercessor

仲介者
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.
彼は二つの家族間の対立を解決するために仲介者として行動しました。
C2 noun /ˈɪntərˌveɪl/

intervale

川沿いの低地、通常は肥沃で平坦
Meaning
A low-lying tract of land along a river, usually fertile and flat.
Example
The farmers cultivated crops on the lush intervale by the river.
農民たちは川沿いの肥沃な土地で作物を育てた。
C2 noun /ˈɪkθiəˌsɔːrz/

ichthyosaurs

イクチオサウルス（絶滅した海の爬虫類）
Meaning
Extinct marine reptiles that resembled fish and dolphins, dominant during the Mesozoic era.
Example
Ichthyosaurs were swift predators of the ancient seas.
イクチオサウルスは古代の海で素早い捕食者でした。
C2 noun /ɪnˈvɛstɪtʃər/

investiture

任命式
Meaning
the formal ceremony of conferring authority, rank, or office
Example
The king held an investiture ceremony for the new knight.
王は新しい騎士のために任命式を開催しました。
C2 verb /aɪˈdɒləˌtraɪz/

idolatrize

偶像崇拝
Meaning
To worship idols; to regard with excessive devotion or admiration.
Example
They began to idolatrize the statue as a deity.
彼らはその像を神として崇拝し始めました。
C2 noun /aɪər/

ire

怒り, 激怒
Meaning
intense anger or rage
Example
The new policy provoked the ire of the employees.
新しい政策は従業員の怒りを引き起こした。
C2 noun /ˌɪlɪbəˈræləti/

illiberality

不寛容
Meaning
The quality of being illiberal; lack of tolerance or generosity.
Example
The illiberality of the new laws alarmed the citizens.
新しい法律の不寛容が市民を驚かせました。
C2 noun /ˌɪnkænˈdɛsəns/

incandescence

白熱光
Meaning
the emission of light from a hot object; brilliance
Example
The incandescence of the candle filled the dark room.
ろうそくの白熱光が暗い部屋を満たしました。
C2 verb /ɪnˈtɜːrpəˌleɪt/

interpolate

挿入する
Meaning
To insert something, often words, into a text or conversation; to estimate values between known data points.
Example
The editor interpolated a missing paragraph into the manuscript.
編集者は原稿に欠落した段落を挿入した。
C2 adjective /ɪnˈsuːpərəbl/

insuperable

克服できない
Meaning
Impossible to overcome or surpass.
Example
The team faced insuperable challenges during the expedition.
チームは遠征中に克服できない課題に直面しました。
C2 adjective /ɪnˈsuːsiənt/

insouciant

無頓着
Meaning
Showing a casual lack of concern; carefree.
Example
He gave an insouciant shrug and walked away.
彼は無頓着に肩をすくめて、歩き去った。
C2 noun /ˈɪn.tɪ.ɡreɪ.tɪv dɪˈpləʊ.mə.si/

integrative diplomacy

統合的外交
Meaning
A diplomatic approach that seeks to combine or coordinate different elements, interests, or parties into a unified whole.
Example
Integrative diplomacy strengthens alliances.
統合的外交は同盟を強化する。
C2 verb /ɪˈnjʊər/

inure

慣れる
Meaning
To become accustomed to something, especially something unpleasant.
Example
Soldiers quickly became inured to the harsh conditions.
兵士たちはすぐに過酷な状況に慣れました。
C2 adjective /ˌɪn.trəˈsɛl.jʊ.lər/

intracellular

細胞内
Meaning
Located or occurring within a cell.
Example
The drug works by targeting intracellular bacteria.
薬は細胞内の細菌をターゲットにして作用します。
C2 noun /ˌɪmbəˈsɪləti/

imbecility

愚かさ
Meaning
Extreme foolishness, stupidity, or weakness of mind.
Example
The plan was abandoned due to its sheer imbecility.
その計画はその愚かさから放棄されました。
C2 noun /ɪˌluːmɪˈnɑːti/

illuminati

イルミナティ
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.
多くの陰謀論はイルミナティを世界を支配する秘密のグループとして扱っている。
C2 noun /ɪnˈvɛktɪv/

invective

侮辱的な言葉
Meaning
Insulting, abusive, or highly critical language.
Example
The politician’s speech was filled with invective against his opponents.
その政治家の演説は、対立候補に対する侮辱的な言葉で満ちていた。
C2 verb /ɪnˈfætʃueɪt/

infatuate

夢中にさせる
Meaning
to inspire with an intense but short-lived passion or admiration
Example
He was infatuated with her beauty.
彼は彼女の美しさに夢中でした。
C2 adjective /ˌɪlˈneɪ.tʃəd/

ill-natured

性格が悪い
Meaning
Having a bad or unpleasant character; unkind or malicious.
Example
He made an ill-natured remark about his colleague.
彼は同僚について悪意のある発言をしました。
C2 noun /ˈaɪdlər/

idler

怠け者
Meaning
A person who avoids work or spends time lazily.
Example
He was known as an idler who wasted his days.
彼は自分の時間を無駄にするアイドラーとして知られていました。
C2 verb /ˌɪntərˈsiːd/

intercede

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.