Insanity
All a b c d e f g h i j k l m n o p q r s t u v w x y z
All CEFR A1 A2 B1 B2 C1 C2
Content locale
EN 英語 BN ベンガル語 HI ヒンディー語 ES スペイン語 FR フランス語 DE ドイツ語 RU ロシア語 ZH 中国語 JA 日本語
All Vocabulary Cards All Vocabularies
C1 noun /ɪnˈsæn.ə.ti/

Insanity

狂気; 精神疾患
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.
弁護人は、被告人が狂気によって無罪であると主張した。
C1 noun /ˌɪnkoʊˈhɪrəns/

incoherence

不整合
Meaning
The quality of being unclear, confused, or lacking logical connection.
Example
His speech was full of incoherence and difficult to follow.
彼のスピーチは不整合で、理解するのが難しかった。
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 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 verb /ɪmˈbɛd/

imbed

埋め込む
Meaning
To fix firmly or deeply in a surrounding mass.
Example
The journalist imbedded himself with the troops to report firsthand.
ジャーナリストは部隊に埋め込まれて、最前線から報告を行った。
C1 adjective /ɪnˈkrɛdjələs/

incredulous

Meaning
unwilling or unable to believe something
Example
He gave her an incredulous look when she claimed she could fly.
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 adjective /ɪnˈdɪɡnənt/

indignant

憤慨した
Meaning
Feeling or showing anger at something considered unfair or unjust.
Example
She was indignant when accused of cheating.
彼女は不正行為を非難されたとき、憤慨していた。
C1 verb /ɪnˈfleɪt/

inflate

膨らませる；水増しする
Meaning
to fill with air or gas so it expands; to increase excessively or artificially
Example
The mechanic inflated the tire to the correct pressure.
整備士はタイヤを適切な空気圧まで膨らませた。
C1 verb /ɪnˈdʌkt/

induct

Meaning
to formally admit someone into a position, organization, or office
Example
She was inducted into the university's honor society.
C1 adjective /ɪnˈdʒʊəriəs/

injurious

有害な
Meaning
Causing or likely to cause harm or damage.
Example
Smoking is injurious to health.
喫煙は健康に有害です。
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 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 noun /ˌɪnkənˈsɪstənsi/

inconsistency

不一致
Meaning
The quality of being contradictory, irregular, or not staying the same.
Example
There is an inconsistency between his words and actions.
彼の言葉と行動には不一致があります。
C1 verb /ɪnˈvɜːrt/

invert

逆さにする
Meaning
To turn something upside down or in the opposite position, order, or direction.
Example
He inverted the glass to let the water drain out.
彼は水が流れ出るようにグラスを逆さまにしました。
C1 verb /ˌɪnstɪˈtjuːʃənəlaɪz/

institutionalize

制度化する
Meaning
to establish something as a formal institution, custom, or practice
Example
The government seeks to institutionalize environmental protection.
政府は環境保護を制度化しようとしています。
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。
C1 adjective /ˌɪntəˈrɑːɡətɪv/

interrogative

疑問の
Meaning
Relating to or conveying a question; in grammar, used to form questions.
Example
She raised an interrogative eyebrow when she heard the news.
彼女はそのニュースを聞いて疑問のまなざしを向けました。
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 /ˈɪnˌmeɪt/

inmate

囚人
Meaning
a person confined to an institution such as a prison or hospital
Example
The prison has over a thousand inmates.
刑務所には千人以上の囚人がいます。
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 /ɪnˈstɪŋk.tɪv/

instinctive

本能的, 自然な, 自動的
Meaning
Based on instinct; done without conscious thought; natural and automatic.
Example
His instinctive reaction saved his life.
彼の本能的な反応は彼の命を救った。
C1 noun ˌɪn.toʊˈneɪ.ʃən

intonation

イントネーション
Meaning
The rise and fall of tone in speech and pronunciation.
Example
Proper intonation enhances the clarity of a speech.
適切なイントネーションはスピーチの明確さを高めます。
C1 noun /ɪnˈsɜːrdʒəns/

insurgence

反乱
Meaning
An act of rebellion or uprising against authority.
Example
The government struggled to contain the growing insurgence.
政府は増大する反乱を抑制するのに苦労した。
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 /ɪˈlɪsɪt/

illicit

不法な
Meaning
Forbidden by law, rules, or custom.
Example
The police shut down the illicit drug operation.
警察は不法な麻薬取引を閉鎖しました。
C1 adjective /ɪnˈstrʌktɪv/

instructive

教育的
Meaning
useful and informative; providing knowledge or instruction
Example
The lecture was highly instructive and engaging.
その講義は非常に教育的で魅力的でした。
C1 noun /ˌɪn.dɪˈsɪʒ.ən/

Indecision

優柔不断; 決断力の欠如; 迷い
Meaning
the inability to make decisions quickly; uncertainty about what to do
Example
Her indecision about which job offer to accept caused her to miss both opportunities.
どの仕事のオファーを受けるかについての優柔不断さが、両方のチャンスを逃す原因となった。
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。
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 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 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 noun ɪnˌɛv.ɪ.təˈbɪl.ɪ.ti

inevitability

避けられない運命
Meaning
The quality of being certain to happen and impossible to avoid or prevent.
Example
The inevitability of change is a part of life.
変化の避けられないことは人生の一部です。
C1 verb /ɪmˈplɔːr/

implore

Meaning
To beg someone earnestly or desperately to do something.
Example
She implored him to stay with her.
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 /ˌɪndɪɡˈneɪʃən/

indignation

憤慨
Meaning
Strong displeasure or anger caused by something unjust, offensive, or insulting.
Example
Public indignation grew after the unfair verdict.
不公平な判決の後で、公衆の憤慨が高まった。
C1 verb /ɪmˈpɒvərɪʃ/

impoverish

貧困にする
Meaning
To make someone poor or reduce the quality or richness of something.
Example
The long war impoverished the entire nation.
長い戦争が国全体を貧困にした。
C1 noun /ɪmˌpɜː.sənˈeɪ.ʃən/

impersonation

なりすまし
Meaning
The action of pretending to be another person for the purpose of entertainment or fraud.
Example
Online impersonation is a serious cybercrime.
オンラインでのなりすましは重大なサイバー犯罪です。
C1 noun /ˌaɪ.diˈɒl.ə.dʒi/

ideology

イデオロギー
Meaning
A system of ideas and ideals, especially one that forms the basis of economic or political theory and policy.
Example
Democracy is based on the ideology of freedom and equality.
民主主義は自由と平等のイデオロギーに基づいています。
C1 adjective /ˌɪrɪˈvɜːrsəbl/

irreversible

不可逆な
Meaning
Not able to be undone, changed, or reversed.
Example
The damage caused by the fire was irreversible.
火事によって生じた損害は不可逆でした。
C1 adjective /ˈɪnsələnt/

insolent

無礼な、傲慢な
Meaning
showing a rude and arrogant lack of respect
Example
The insolent student refused to follow the teacher's instructions.
その無礼な学生は教師の指示に従うことを拒否した。
C1 adjective /ɪnˈseɪʃəbl̩/

insatiable

満たされない
Meaning
impossible to satisfy; always wanting more
Example
Her insatiable curiosity drove her to read every book in the library.
彼女の満たされない好奇心は、図書館のすべての本を読むように彼女を駆り立てた。
C1 adjective /ˌɪnkənˈkluːsɪv/

inconclusive

結論が出ていない
Meaning
Not leading to a definite result or decision.
Example
The investigation remained inconclusive due to a lack of evidence.
証拠の不足により、調査は結論が出ていないままでした。
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 adjective /ɪnˈflɛksəbl/

inflexible

柔軟性がない
Meaning
Not able to bend or change; unwilling to change ideas or behavior.
Example
His inflexible attitude made negotiations difficult.
彼の柔軟性がない態度は交渉を難しくしました。
C1 adjective /ɪnˈsɒlvənt/

insolvent

破産
Meaning
unable to pay debts owed
Example
The insolvent firm could not meet its financial obligations.
破産した企業は財務義務を果たせなかった。
C1 verb /ˈɪnstɪˌɡeɪt/

instigate

扇動する
Meaning
To bring about or initiate an action, often something negative.
Example
He was accused of instigating the riot.
彼は暴動を扇動したとして告発された。
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。
C1 adjective, noun /ˈɪnvəlɪd/ (adjective), /ɪnˈvælɪd/ (noun)

invalid

無効
Meaning
Not valid; having no force or effect. Also refers to a person too weak or ill to care for themselves.
Example
The court declared the contract invalid.
裁判所は契約を無効と宣言した。
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。
C1 adverb ɪnˈtrɪn.zɪ.kli

intrinsically

本質的に
Meaning
In a way that is naturally or inherently part of something's essential nature.
Example
Some people are intrinsically motivated to learn.
いくつかの人々は本質的に学ぶことに動機づけられている。
C1 noun /ɪˈmɜː.ʃən/

immersion

没入
Meaning
Complete engagement in an environment or experience.
Example
Immersion in VR games makes users feel like they are inside the virtual world.
VRゲームへの没入は、ユーザーが仮想世界にいるように感じさせます。
C1 noun ɪnˈdɪdʒɪnəs trəˈdɪʃənz

Indigenous Traditions

先住民の伝統
Meaning
Cultural practices, beliefs, and customs that have been passed down through generations among native peoples.
Example
Indigenous traditions in the Chittagong Hill Tracts are unique.
チッタゴン丘陵地帯の先住民の伝統はユニークです。
C1 adjective /ɪnˈæk.tɪv/

Inactive

非アクティブ
Meaning
not active; not working; dormant; idle
Example
The volcano has been inactive for over a century.
この火山は1世紀以上も活動していない。
C1 verb /ɪnˈskraɪb/

inscribe

刻む
Meaning
to write or carve words or symbols on a surface
Example
They inscribed her name on the trophy.
彼らはトロフィーに彼女の名前を刻みました。
C1 adjective /ɪnˈfriːkwənt/

infrequent

稀な
Meaning
Happening rarely or not often.
Example
He made infrequent visits to his hometown after moving abroad.
彼は海外に移住した後、故郷にあまり頻繁に訪れることはありませんでした。
C1 noun /ɪnˈkɒmpɪtəns/

incompetence

無能
Meaning
Lack of ability, skill, or effectiveness in doing something.
Example
The project failed due to the manager’s incompetence.
プロジェクトはマネージャーの無能のため失敗しました。
C1 noun /ˌɪntərˈmɪʃən/

intermission

休憩
Meaning
A pause or break, especially during a performance or event.
Example
The play had a twenty-minute intermission.
その劇には20分間の休憩がありました。
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 /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 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 adjective; noun /ɪˈmɔːrtl/

immortal

不死の
Meaning
living forever; never dying; lasting forever in fame or memory
Example
Legends often describe heroes as immortal beings who never die.
伝説では英雄は不死の存在だとされる。
C1 noun /ˈɪmɪdʒəri/

imagery

イメージ
Meaning
visually descriptive or figurative language, especially in a literary work
Example
The poet's use of imagery brought the scene to life.
詩人のイメージの使用は、シーンに命を吹き込みました。
C1 adverb /ˈɪnwərdli/

inwardly

内面的に
Meaning
In the mind or spirit; not outwardly visible.
Example
She smiled outwardly but inwardly she was worried.
彼女は外見では微笑んだが、内心では心配していた。
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。
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 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 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 ɪnˈsɛpʃən

inception

始まり
Meaning
The establishment or starting point of an institution or activity.
Example
The inception of the company marked a new era in the industry.
その企業のインセプションは業界に新しい時代を築きました。
C1 adjective /ˌɪn.səˈbɔːr.dɪ.nət/

insubordinate

命令不服従
Meaning
Defiant of authority; disobedient to orders.
Example
The insubordinate employee refused to follow the manager's instructions.
命令不服従の従業員は、マネージャーの指示に従うことを拒否した。
C1 adjective /ˌɪndɪˈskriːt/

indiscreet

軽率
Meaning
Not careful in what one says or does, likely to reveal secrets or offend.
Example
It was indiscreet of him to mention the plan in public.
公衆の面前で計画について言及するのは軽率だった。
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 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 /ɪnˈfɜː.mə.ti/

Infirmity

虚弱; 病気; 衰弱
Meaning
physical or mental weakness; a disease or ailment; frailty
Example
Despite his advanced age and various infirmities, he remained mentally sharp and alert.
高齢で多くの病気を抱えていても、彼は精神的に鋭く、警戒心を持ち続けました。
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 verb /ɪmˈpiːd/

impede

妨げる
Meaning
To obstruct or hinder the progress or development of something.
Example
Lack of funds can impede business growth.
資金不足はビジネスの成長を妨げる可能性があります。
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 adjective /ɪnˈtɒl.ər.ə.bəl/

Intolerable

耐えられない
Meaning
unable to be endured; extremely unpleasant or painful
Example
The noise from the construction site was intolerable.
工事現場の騒音は耐えられないほどひどかった。
C1 verb /ˌɪntəˈsɛkt/

intersect

交差する
Meaning
to cross or pass through each other
Example
The two roads intersect at the city center.
二つの道路は市内中心で交差する。
C1 verb /ˈɪnfɪltreɪt/

infiltrate

浸透
Meaning
to secretly enter or gain access to a place or group
Example
The spies managed to infiltrate the enemy base.
スパイたちは敵基地に infiltrate できた。
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 adjective /ˌɪnədˈvɜːrtənt/

inadvertent

意図しない, 不注意な
Meaning
Not resulting from or achieved through deliberate planning; unintentional.
Example
Her inadvertent mistake caused a delay in the project.
彼女の不注意なミスがプロジェクトの遅延を引き起こしました。
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 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 adjective /ˌɪntərˈtʃeɪndʒəbl/

interchangeable

交換可能な
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.
これらの機械部品は交換可能なため、簡単に交換できます。
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 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 noun /ˈɪnstɪˌɡeɪtər/

instigator

扇動者
Meaning
A person who brings about or initiates something, usually something bad.
Example
The police identified him as the instigator of the violence.
警察は彼を暴力の扇動者として特定しました。
C1 adverb /ˌɪnsɪˈdɛntəli/

incidentally

ちなみに
Meaning
by the way; used to introduce a remark not directly related to the main subject
Example
Incidentally, did you know that she studied in Paris?
ちなみに、彼女がパリで勉強していたことを知っていましたか？
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 noun /ˌɪrɪˌspɒnsəˈbɪləti/

irresponsibility

無責任
Meaning
lack of responsibility or accountability; failure to act in a reliable or sensible way
Example
The accident was caused by his irresponsibility at work.
その事故は彼の職場での無責任さが原因でした。
C1 noun /ɪmˈpɜːrtɪnəns/

impertinence

無礼
Meaning
lack of respect; rudeness
Example
The teacher was shocked by the student's impertinence.
教師は生徒の無礼さに驚いた。
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 /ɪˈmoʊbəl/

immobile

動けない
Meaning
unable to move or be moved
Example
After the accident, he was immobile for weeks.
事故の後、彼は数週間動けなかった。
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 /ɪnˈsʌf.ər.ə.bəl/

insufferable

耐え難い
Meaning
Too extreme to bear; intolerable.
Example
The heat during the summer was insufferable.
夏の暑さは耐え難かった。
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 /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。
C1 adjective /ˌɪnɪkˈskjuːzəbl/

inexcusable

許しがたい
Meaning
Too bad to be justified or overlooked; unforgivable.
Example
His rude behavior was inexcusable.
彼の無礼な行動は許しがたいものでした。
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 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。
C1 noun ˌɪntədɪˈpɛndənsi

interdependency

相互依存
Meaning
The dependence of two or more people or things on each other.
Example
The interdependency of the countries led to greater cooperation.
国々の相互依存は、より大きな協力を生み出しました。
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 noun /ɪmˈpɒs.tər/

Impostor

詐欺師; 偽者
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.
詐欺師は医者だとみんなを納得させましたが、彼の偽の資格が発覚するまでそれが続きました。
C1 adjective /ˈɪnbɔːrn/

Inborn

生まれつきの; 生来の; 内在的な
Meaning
existing from birth; natural; inherent
Example
She has an inborn talent for music.
彼女は音楽のための生まれつきの才能を持っています。
C1 noun ˈɪm.pɪ.təs

impetus

推進力
Meaning
The force or motivation that drives something forward; momentum.
Example
The new policy provided an impetus for economic growth.
新しい政策は経済成長のための推進力を提供しました。
C1 noun /ˌɪn.dʒəˈnjuː.ɪ.ti/

ingenuity

独創性
Meaning
The quality of being clever, original, and inventive.
Example
His ingenuity led to groundbreaking innovations.
彼の創意工夫は画期的な革新を生み出しました。
C1 verb /ɪmˈpɛrɪl/

imperil

危険にさらす
Meaning
To put in danger or at risk.
Example
Reckless driving can imperil the lives of others.
無謀な運転は他人の命を危険にさらす可能性があります。
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 adjective /ɪnˈtjuː.ɪ.tɪv/

intuitive

直感的
Meaning
Based on instinctive understanding rather than reasoning.
Example
The software has an intuitive design that makes it easy to use.
そのソフトウェアは直感的なデザインを持っており、使いやすいです。
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 /ˌɪnkəmˈpætəbl/

incompatible

互換性がない
Meaning
Not able to exist or work together without conflict.
Example
Their personalities were completely incompatible.
彼らの性格は完全に互換性がなかった。
C1 adjective /ɪˈrɛfjʊtəbəl/

Irrefutable

反論できない
Meaning
impossible to deny or disprove; undeniable
Example
The evidence against him was irrefutable.
彼に対する証拠は否定できないものでした。
C1 adjective ɪnˈkʌm.bənt

incumbent

義務的な
Meaning
necessary for (someone) as a duty or responsibility.
Example
It is incumbent upon all citizens to obey the law.
すべての市民が法律を守るのは義務である。
C1 noun /ˌɪnkwɪˈzɪʃən/

inquisition

尋問
Meaning
A prolonged and intense questioning or investigation, often harsh in nature.
Example
The journalist faced an inquisition from the panel about his sources.
ジャーナリストは、自分の情報源に関するパネルからの厳しい尋問に直面した。
C1 noun/verb /ˈɪnsɛns/

incense

お香 / 激怒させる
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.
お香の香りが寺院を満たしましたが、彼の失礼な言葉は彼女を激怒させました。
C1 adjective, noun /ɪnˈdɪkətɪv/

indicative

指示的
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.
彼のトーンは彼のフラストレーションを示していた。
C1 adjective /ɪnˈveə.ri.ə.bəl/

Invariable

不変の; 一定の; 常に同じ
Meaning
never changing; constant; always the same
Example
His invariable routine includes morning exercise and coffee.
彼の不変のルーチンには、朝の運動とコーヒーが含まれています。
C1 noun /ˌɪnkjʊˈbeɪʃən/

incubation

卵、細胞、または生物を適切な条件で発展させるプロセス
Meaning
the process of keeping eggs, cells, or organisms in the right conditions for development
Example
The incubation of the eggs lasted for three weeks.
卵のインキュベーションは三週間続きました。
C1 verb ɪˈnɪʃɪeɪtɪd

initiated

開始された
Meaning
Caused a process or action to begin; started something.
Example
The project was initiated to enhance marine biodiversity.
プロジェクトは海洋生物多様性を向上させるために開始されました。
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。