impotent
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C1 adjective /ˈɪmpətənt/

impotent

無力
Meaning
Lacking power, ability, or strength to take effective action.
Example
The citizens felt impotent against the corrupt system.
市民は腐敗したシステムに対して無力だと感じた。
C1 noun /aɪˈdiː.ə.lɪ.zəm/

Idealism

理想主義
Meaning
the pursuit of high principles and noble goals; unrealistic pursuit of perfection
Example
His youthful idealism motivated him to join various social justice movements.
彼の若い理想主義は、彼を様々な社会正義運動に参加させる原動力となった。
C1 adjective /ɪnˈɡreɪnd/

ingrained

根強い
Meaning
Firmly fixed or established; deeply rooted and difficult to change.
Example
His ingrained habits were hard to break.
彼の根強い習慣は壊すのが難しかった。
B1 noun /ɪmˈprɛʃən/

impression

印象, 概念
Meaning
an idea, feeling, or opinion about something or someone
Example
The book gave me a good first impression.
その本は私に良い最初の印象を与えました。
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。
C1 adjective /ˌɪndɪˈskrɪmɪnət/

indiscriminate

無差別
Meaning
Done without careful judgment; random or haphazard.
Example
The indiscriminate use of pesticides harms the environment.
農薬の無差別な使用は環境に害を与えます。
C2 noun /ɪnˈtɒksɪkənt/

intoxicant

酔わせる物質
Meaning
a substance, especially alcohol or a drug, that causes intoxication
Example
Alcohol is the most commonly used intoxicant in many cultures.
アルコールは多くの文化で最も一般的に使用される酔わせる物質です。
C2 adjective /ˌaɪdəˈlɑːtrɪəs/

idolatrious

偶像崇拝的な
Meaning
Excessively devoted or reverent towards idols or false gods.
Example
The ancient tribe was known for its idolatrious practices.
その古代の部族は偶像崇拝的な習慣で知られていました。
C1 noun ˌɪn.fɪlˈtreɪ.ʃən

infiltration

浸透、秘密のアクセス
Meaning
The process of entering or gaining access to an organization or place surreptitiously.
Example
Cybersecurity prevents infiltration into sensitive data.
サイバーセキュリティは、機密データへの浸透を防ぎます。
A2 noun /ˌɪnvɪˈteɪʃən/

invitation

幸せ
Meaning
a written or spoken request to attend an event or to participate in something
Example
She sent me an invitation to her wedding.
彼女は賞を受け取ったとき、自分の幸せを隠すことができませんでした。
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 noun /ɪˈrɛlɪvənsi/

irrelevancy

無関係性
Meaning
the state of being unrelated or unimportant to the matter at hand
Example
The judge dismissed the argument because of its irrelevancy to the case.
裁判官はその主張が事件と無関係であるとして退けた。
B1 noun /ˈɪnpʊt/

input

入力、提供された情報
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.
マネージャーは新しいプロジェクトに対する全員のインプットを求めました。
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 noun /ˌɪməʊˈbɪləti/

immobility

不動
Meaning
The state of being unable to move.
Example
After the accident, she suffered from immobility in her legs.
事故の後、彼女は足の不動に苦しみました。
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。
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。
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。
B2 verb /ɪnˈstrʌkt/

instruct

指示する
Meaning
to teach; to give directions
Example
The teacher instructed the students carefully.
先生は生徒に注意深く指示しました。
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 adjective /ɪmˈplækəbl/

implacable

容赦しない
Meaning
unable to be appeased, calmed, or pacified
Example
The soldiers faced an implacable enemy who refused to surrender.
兵士たちは降伏を拒否した容赦しない敵に直面した。
B2 noun ɪnˈdʒʌstɪs

injustice

不正義
Meaning
Lack of fairness or justice; the practice of being unjust or unfair.
Example
The story portrays the injustices faced by the common people.
物語は一般の人々が直面する不正義を描いています。
B2 adjective /ɪˈmætʃʊr/

Immature

未熟; 完全に発達していない; 子供っぽい
Meaning
not fully developed; lacking emotional or intellectual development; childish
Example
His immature behavior during the meeting disappointed everyone.
会議中の彼の未熟な行動は、皆を失望させました。
C2 adjective /ˌɪnɪkˈspiːdiənt/

inexpedient

不適切
Meaning
Not advisable, suitable, or practical in the circumstances.
Example
It would be inexpedient to invest without proper research.
適切な調査なしで投資することは不適切です。
C1 adjective /ɪnˈhɪbɪtɪd/

inhibited

抑制された
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.
彼は自分の本当の感情を表現するにはあまりにも抑制されていた。
C2 adjective /ˌɪnˈekspɜːrt/

inexpert

未熟な
Meaning
not skilled or experienced; lacking expertise
Example
The inexpert handling of the machine caused several mistakes.
機械の未熟な扱いがいくつかのミスを引き起こした。
B1 verb /ɪnˈfɔ:m/

inform

通知する
Meaning
to tell someone about something; to give information
Example
Please inform me when you arrive at the airport.
空港に到着したら、私に通知してください。
B2 noun /ˈɪnfənt/

infant

乳児
Meaning
A very young child or baby.
Example
The infant was sleeping peacefully in the cradle.
乳児はゆりかごで静かに眠っていました。
C2 noun /ˌɪnkəˈpæsəti/

incapacity

無能力
Meaning
the lack of ability, power, or fitness to do something
Example
His mental incapacity prevented him from making important decisions.
彼の精神的無能力は、重要な決定を下すのを妨げました。
B2 adjective /ˈɪɡ.nər.ənt/

Ignorant

無知
Meaning
lacking knowledge or awareness; uninformed
Example
She was ignorant about the new technology trends.
彼女は新しい技術のトレンドについて無知でした。
B2 verb /ɪmˈpoʊzd/

imposed

課す
Meaning
forced something to be accepted or put in place
Example
The government imposed new regulations on the industry.
政府は産業に新しい規制を課した。
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。
A2 verb /ɪnˈvaɪtɪd/

invited

招待された
Meaning
asked someone formally or politely to go somewhere or do something
Example
She was invited to the party.
彼女はパーティーに招待された。
C1 verb /ɪnˈkɑːrsəreɪt/

incarcerate

投獄する
Meaning
to imprison or confine someone
Example
The authorities incarcerated the criminal after the trial.
当局は裁判後に犯罪者を投獄しました。
B2 adjective /ˈaɪ.dəl/

Idle

怠惰な; 非活動的な; 使われていない
Meaning
lazy; inactive; not working or being used
Example
The factory workers were idle during the strike.
工場の労働者はストライキ中に暇だった。
B2 adjective /ɪnˈsɛnsətɪv/

insensitive

無神経な
Meaning
Showing or feeling no concern for others' feelings.
Example
His insensitive comment hurt her deeply.
彼の無神経なコメントは彼女を深く傷つけました。
C1 adjective /ɪˈlɒdʒ.ɪ.kəl/

Illogical

非論理的
Meaning
not reasonable or sensible; lacking logic
Example
It would be illogical to go swimming in such cold weather.
こんなに寒い天気で泳ぐのは非論理的です。
C1 adjective ˈɪn.tər.ɪm

interim

暫定的
Meaning
In or for the intervening period; provisional or temporary.
Example
Interim governments manage transitional phases.
暫定政府は移行段階を管理します。
C2 verb /ˌɪnkəˈpæsɪteɪt/

incapacitate

無力化する
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.
その重傷はプレーヤーをシーズンの残りの期間無力化させた。
C1 noun /ɪnˈfɜːməri/

infirmary

診療所
Meaning
A hospital or place where the sick or injured are cared for.
Example
The school had an infirmary for minor injuries.
学校には軽傷のための診療所がありました。
C2 verb /ɪˈmjʊər/

immure

閉じ込める
Meaning
to confine or enclose someone against their will
Example
The prisoner was immured in a dark cell.
囚人は暗い監房に閉じ込められた。
B1 adjective /ɪnˈvɑːlvd/

involved

関与した
Meaning
complicated or engaged in something
Example
She was deeply involved in community service.
彼女は地域社会の奉仕活動に深く関与していた。
C2 adjective /ɪnˈtɛsteɪt/

intestate

遺言なしで死亡
Meaning
Having died without leaving a valid will.
Example
She died intestate, so her assets were distributed by law.
彼女は遺言なしで死亡したため、財産は法に従って分配されました。
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 /ɪˈnuːmərəbəl/

Innumerable

無数; 数えきれない; 無限
Meaning
too many to be counted; countless; infinite in number
Example
There are innumerable stars in the night sky that we cannot see with our naked eyes.
夜空には数えきれない星があり、私たちは裸眼では見ることができません。
C1 adjective /ɪˈneɪn/

inane

無意味な, 馬鹿な
Meaning
lacking sense, meaning, or significance; silly or pointless
Example
The movie was criticized for its inane dialogue.
その映画は無意味なセリフで批判された。
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。
B2 noun ɪnˌdʌstrɪəlaɪˈzeɪʃən

industrialization

産業化
Meaning
The development of industries in a country or region on a wide scale.
Example
Industrialization changed the global economy dramatically.
産業化は世界経済を劇的に変えました。
C1 noun /ɪˌreɡjəˈlærɪti/

irregularity

不規則性
Meaning
lack of regularity or consistency; a deviation from what is normal, expected, or orderly
Example
The audit revealed several financial irregularities in the company’s records.
監査により、その会社の記録にいくつかの財務上の不規則性が明らかになった。
C1 adjective ˌɪn.trəˈspek.tɪv

introspective

内省的
Meaning
Characterized by or given to introspection; examining one's own thoughts and feelings.
Example
Writers tend to be highly introspective individuals.
作家はしばしば非常に内省的な人々である。
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 /ˌɪn.trəˈvɜːr.ʒən/

introversion

内向
Meaning
The tendency to be inward-looking and shy, preferring solitary activities.
Example
Her introversion made it difficult for her to enjoy large parties.
彼女の内向的な性格は、大きなパーティーを楽しむのを難しくした。
C1 noun /ɪmˈpɛd.ɪ.mənt/

impediment

障害
Meaning
A hindrance or obstruction in doing something; something that prevents progress.
Example
Lack of funds is a major impediment to the project.
資金不足はプロジェクトの大きな障害です。
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.
B2 noun ˌɪn.əˈveɪ.ʃən

innovation

革新
Meaning
The action or process of innovating; a new method, idea, product, etc.
Example
Innovation drives solutions to global challenges.
革新は世界的な課題への解決策を促進します。
A1 pronoun /ɪt/

it

それ
Meaning
used to refer to a thing, animal, or idea previously mentioned or easily identified
Example
It is raining outside.
外では雨が降っています。
C1 adjective /ˈɜːrksəm/

irksome

迷惑的
Meaning
annoying or irritating
Example
Waiting in a long line is one of the most irksome tasks.
長い列に並んでいるのは、最も迷惑な作業の一つです。
B2 adjective /ɪnˈfɔːrmətɪv/

Informative

有益な
Meaning
giving or providing useful information; educational; instructive
Example
The documentary was very informative and educational.
そのドキュメンタリーはとても有益で教育的でした。
C2 noun /ˈɪmpjʊdəns/

impudence

厚かましさ
Meaning
Rude and disrespectful behavior.
Example
The student's impudence shocked the entire class.
その学生の厚かましさはクラス全体を驚かせた。
B2 adjective /ɪmˈprɒp.ər/

Improper

不適切な; 不正確な; 不適当な
Meaning
inappropriate; incorrect; not suitable
Example
It would be improper to discuss personal matters in a business meeting.
ビジネス会議で個人的な事柄を議論するのは不適切です。
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 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。
C2 adjective /ɪmˈplaɪəbl/

impliable

暗示可能な
Meaning
Capable of being implied or suggested.
Example
The meaning of the statement is not directly clear but is impliable from the context.
その声明の意味は直接的には明確ではないが、文脈から推測可能である。
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 adjective /ɪmˈpæsɪbəl/

impassible

無痛性
Meaning
Incapable of suffering or feeling pain (used mainly in theological or philosophical contexts).
Example
Some philosophers argue that God is impassible and cannot experience human emotions.
一部の哲学者は、神は無痛性であり、人間の感情を感じることはできないと主張しています。
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。
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。
B2 noun /ɪnˈtɒlərəns/

intolerance

不寛容
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.
リーダーは他の宗教に対する不寛容さで批判されました。
B2 noun /ɪnˈkluːʒən/

inclusion

インクルージョン
Meaning
the action or state of including or being included within a group or structure
Example
Diversity and inclusion are key values in modern workplaces.
多様性とインクルージョンは現代の職場における重要な価値観です。
C2 adjective /ɪnˈseɪʃiət/

insatiate

飽くなき
Meaning
impossible to satisfy; always wanting more
Example
He had an insatiate desire for power.
彼は権力への飽くなき欲望を持っていた。
C2 noun /ˌɪkθiˈɒlədʒɪst/

ichthyologist

魚類学者
Meaning
A scientist who studies fish.
Example
The ichthyologist discovered a new species of fish in the river.
魚類学者は川で新しい魚の種を発見しました。
C2 noun /ɪmˈpruː.dəns/

Imprudence

無分別; 不注意; 軽率
Meaning
the quality of being imprudent; lack of care for consequences; recklessness
Example
His financial imprudence led to bankruptcy within just two years.
彼の財務の無分別は、わずか2年で破産を招いた。
C1 adjective ɪnˈdʒiː.ni.əs

ingenious

独創的
Meaning
Showing inventiveness and skill; clever, original, and inventive.
Example
His ingenious ideas transformed modern physics.
彼の独創的なアイデアは現代物理学を変えました。
A2 adjective, noun /ɪˈtæliən/

italian

幸福
Meaning
relating to Italy, its people, or its language; a person from Italy
Example
She loves Italian food.
彼女は賞を受け取ったとき、自分の幸せを隠せませんでした。
C2 noun /ˌɪntərˈrɛɡnəm/

interregnum

政権空白期
Meaning
A period between rulers or governments when normal leadership is suspended.
Example
The country faced instability during the interregnum after the king’s death.
国王の死後、国は政権空白期に不安定さに直面した。
C1 adjective /ɪmˈprɒbəbl/

improbable

あり得ない
Meaning
Not likely to be true or to happen.
Example
It seems improbable that he will arrive on time.
彼が時間通りに到着するのはあり得ないようだ。
B1 verb ɪnˈspaɪər

inspire

インスパイアする
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.
アルテミスは未来の世代にインスパイアを与えようとしています。
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。
B2 noun /ɪsˈlɑːm/

islam

イスラム教
Meaning
the religion founded by the Prophet Muhammad, based on belief in one God (Allah)
Example
Islam emphasizes peace, justice, and compassion.
イスラム教は平和、正義、そして慈悲を強調します。
C1 adverb, adjective /ˌɪnkɑːɡˈniːtoʊ/

incognito

インコグニート
Meaning
In disguise or with one's identity concealed.
Example
The celebrity traveled incognito to avoid the paparazzi.
有名人はパパラッチを避けるためにインコグニートで旅行した。
C2 noun /ˈænʒənuː/

ingenue

無邪気な若い女性
Meaning
an innocent, naïve young woman, especially as represented in literature or theater
Example
She played the role of the ingénue in the play with great charm.
彼女は劇で無邪気な若い女性の役を演じ、大きな魅力を発揮しました。
C1 noun /ɪnˌkɑːsəˈreɪʃən/

incarceration

投獄
Meaning
the state of being imprisoned or confined
Example
The criminal faced years of incarceration for his crimes.
犯人はその犯罪のために長年の投獄を受けた。
C1 verb /ɪnˈvoʊk/

invoke

呼び出す
Meaning
to call upon a higher power, authority, or principle for help, support, or justification
Example
The lawyer invoked the constitution to defend his client.
弁護士は憲法を引き合いに出して自分のクライアントを守った。
C2 noun /ˌɪnkænˈteɪʃən/

incantation

呪文
Meaning
a series of words used as a magic spell or charm
Example
The wizard chanted an incantation to summon the spirits.
魔法使いは霊を呼び出すために呪文を唱えました。
B1 adjective /ɪmˈpres.ɪv/

Impressive

印象的な
Meaning
striking; remarkable; having the ability to impress
Example
Her impressive performance earned her a standing ovation.
彼女の印象的な演技はスタンディングオベーションを受けた。
B1 adjective ˌɪn.dɪˈpen.dənt

independent

独立
Meaning
Not depending on another for livelihood or subsistence; free from outside control; not subject to another's authority.
Example
An independent institution ensures transparency in governance.
独立した機関は、ガバナンスの透明性を保証します。
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。
C2 noun /ˈaɪsinəs/

iciness

冷たさ
Meaning
The state of being cold in manner or temperature.
Example
There was a distinct iciness in his voice.
彼の声には明確な冷たさがあった。
C1 verb ɪmˈbjuː

Imbue

誰かの心にアイデアや感情を深く浸透させる
Meaning
Mixing some idea or feeling deeply into someone's mind
Example
The teacher tried to imbue students with a love for learning.
教師は学生に学びへの愛を伝えようとした。
A1 noun /aɪs/

Ice

氷
Meaning
water that has frozen and become solid
Example
The ice in my drink melted quickly in the hot weather.
私の飲み物の氷は暑い天気で素早く溶けました。
A2 noun /ˈɪʃ.uːz/

issues

問題
Meaning
Important topics or problems for debate or discussion.
Example
Health issues from pollution are increasing.
汚染による健康問題が増加しています。
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。
B1 noun /ˌɪntərˈækʃən/

interaction

相互作用
Meaning
The process of people or things acting upon or influencing each other.
Example
The teacher encouraged more interaction between students.
教師は生徒間のさらなるインタラクションを促進しました。
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 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。
B2 verb /ɪnˈspekt/

inspect

検査する
Meaning
to examine something carefully to check for problems or faults
Example
The engineer will inspect the building for structural damage.
エンジニアは建物の構造的な損傷を検査します。
C1 noun /ˌɪməˈtjʊərəti/

immaturity

未熟さ
Meaning
the state of not being fully developed emotionally, mentally, or physically; lack of maturity
Example
His immaturity made it difficult for him to handle responsibility.
彼の未熟さは責任を果たすことを難しくした。
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。
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。
C1 adjective ɪnˈsaɪ.sɪv

incisive

鋭い
Meaning
Intelligently analytical and clear-thinking; showing clear thought and good understanding of what is important.
Example
His incisive comments revealed the core issues.
彼の鋭いコメントは核心的な問題を明らかにしました。
C1 noun /ɪnˈfjuːʒən/

infusion

注入
Meaning
the act of introducing something into another; a drink made by steeping leaves or herbs in liquid
Example
She prepared a calming infusion of chamomile tea.
彼女はカモミールティーの落ち着く注入を準備しました。
B2 noun /ˌɪm.ɪˈteɪ.ʃən/

Imitation

模倣; コピー; レプリカ
Meaning
the action of using someone or something as a model; a copy of something original
Example
His imitation of the famous actor was so good that everyone burst into laughter.
彼の有名な俳優のイミテーションはとても上手で、みんなが笑い出しました。
C1 noun /ˌɪn.səˌbɔːr.dɪˈneɪ.ʃən/

insubordination

反抗
Meaning
Defiance of authority; refusal to obey orders.
Example
The soldier was punished for insubordination during the mission.
その兵士はミッション中の反抗で罰せられました。
C1 noun /ˈɪn.trə.vɜːrt/

introvert

内向的
Meaning
A person who tends to be shy and prefers spending time alone rather than in groups.
Example
As an introvert, he preferred reading over attending parties.
内向的な性格として、パーティに参加するよりも読書の方が好きでした。
C1 verb /ˈɪtəreɪt/

iterate

反復する
Meaning
To repeat a process or statement, often to improve or refine.
Example
The software team will iterate the design until it meets user needs.
ソフトウェアチームは、ユーザーのニーズを満たすまでデザインを繰り返します。
C2 adjective /ɪɡˈnoʊ.bəl/

Ignoble

卑劣; 恥ずべき; 不名誉
Meaning
dishonorable; not noble in character; base or mean
Example
His ignoble actions betrayed his friends' trust.
彼の卑劣な行動は友人たちの信頼を裏切った。
C1 verb /ɪnˈterəˌɡeɪt/

interrogate

尋問する
Meaning
to ask someone questions in a thorough and formal way; to question intensively
Example
The police interrogated the suspect for hours.
警察は容疑者を何時間も尋問した。
C1 noun /ɪmˈpjʊərəti/

impurity

不純物
Meaning
the state of being unclean or contaminated; a substance that makes something impure
Example
The scientist removed every impurity from the water sample.
科学者は水のサンプルからすべての不純物を取り除いた。
A2 adjective /ɪmˈpɑːsəbl/

impossible

不可能
Meaning
not able to occur, exist, or be done
Example
It is impossible to finish this work in one day.
この仕事を1日で終わらせるのは不可能です。
C2 adverb /ɪnˈdjuːbɪtəbli/

indubitably

疑いなく
Meaning
Without a doubt; certainly.
Example
She is indubitably the best candidate for the job.
彼女は疑いなくその仕事の最良の候補者です。
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。
B2 adjective /ˌɪnsəˈfɪʃənt/

insufficient

不十分
Meaning
Not enough; inadequate.
Example
His explanation was insufficient to clear the confusion.
彼の説明は混乱を解消するには不十分でした。
C1 noun /ɪnˈdɪɡ.nə.ti/

Indignity

屈辱
Meaning
treatment or circumstances that cause one to feel shame or loss of dignity; humiliation
Example
She refused to suffer the indignity of being searched without proper cause.
彼女は正当な理由もなく荷物検査を受けるという屈辱に耐えることを拒んだ。
B1 noun ɪˈnɪʃətɪvz

initiatives

イニシアティブ
Meaning
Actions or strategies designed to resolve a difficulty or improve a situation; programs or projects.
Example
Community initiatives benefit underprivileged groups.
コミュニティのイニシアティブは恵まれないグループに利益をもたらす。
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。
B2 adjective /ɪnˈklaɪnd/

inclined

傾向がある
Meaning
having a tendency or disposition toward something
Example
He is inclined to help those in need.
彼は困っている人々を助ける傾向がある。
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。
C2 adjective /ɪˈnɪm.ɪ.tə.bəl/

inimitable

比類のない
Meaning
So good or unusual as to be impossible to copy; unique.
Example
His inimitable writing style made him a literary legend.
彼の比類のない筆致が彼を文学の伝説にした。
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 verb /ɪmˈpɛər/

impair

損なう
Meaning
to weaken or damage something, especially a function or ability
Example
Smoking can impair your lung capacity.
喫煙は肺活量を害する可能性があります。
C2 adjective ɪnˈdɒm.ɪ.tə.bəl

indomitable

不屈の
Meaning
Impossible to subdue or defeat.
Example
Her indomitable spirit helped her overcome adversity.
彼女の不屈の精神が彼女を逆境を克服させた。