infiltrate
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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 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 /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 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 /ɪnˈsɛp(ə)rəbəl/

inseparable

切り離せない
Meaning
Unable to be separated or always together.
Example
The two friends have been inseparable since childhood.
二人の友達は子供の頃から切り離せないです。
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 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 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 verb /ˈɪnsjuleɪt/

insulate

Meaning
To protect something by covering it, especially to prevent heat, sound, or electricity from escaping or entering.
Example
The house was insulated to reduce heating costs.
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 /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 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 adjective /ɪˈnɒkjuəs/

innocuous

無害な
Meaning
Not harmful or offensive.
Example
His remark was completely innocuous and not meant to offend anyone.
彼の発言は完全に無害で、誰かを傷つける意図はなかった。
C1 adjective /ˌɪnstənˈteɪniəs/

instantaneous

即時
Meaning
Happening immediately, without any delay.
Example
The change in temperature was almost instantaneous.
温度の変化はほぼ即時でした。
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。
C1 noun /ˌɪnflɛksɪˈbɪlɪti/

inflexibility

柔軟性の欠如
Meaning
the quality of being rigid or unwilling to change; lack of adaptability
Example
The inflexibility of the rules caused unnecessary delays.
規則の柔軟性の欠如が不要な遅れを引き起こした。
C1 adjective /ɪmˈpɛtʃ.u.əs/

impetuous

衝動的な
Meaning
Acting or done quickly and without thought or care; impulsive.
Example
His impetuous decision led to unexpected consequences.
彼の衝動的な決断は予想外の結果を招いた。
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 adjective /ˌɪnədˈvaɪzəbl/

inadvisable

推奨されない
Meaning
Not recommended; likely to have undesirable consequences.
Example
It is inadvisable to drive in such heavy rain.
このような大雨の中で運転するのは推奨されません。
C1 adjective /ɪmˈpɜːmiəbl/

impermeable

不透水の
Meaning
Not allowing fluid or gas to pass through.
Example
The container is made of impermeable plastic.
その容器は不透水のプラスチックでできています。
C1 adjective /ɪnˈkɒmpɪtənt/

incompetent

Meaning
Lacking the necessary ability or skills to do something successfully.
Example
He was fired because he was incompetent at his job.
C1 noun /ɪmˈbæl.əns/

Imbalance

不均衡
Meaning
lack of proportion or relation between corresponding things; unequal distribution
Example
The doctor said the patient's dizziness was caused by an inner ear imbalance.
医者は患者のめまいが内耳の不均衡によって引き起こされたと言いました。
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 adverb /ˌɪn.ədˈvɜːr.tənt.li/

Inadvertently

うっかり; ついうっかり; 誤って
Meaning
without being aware of what you are doing; unintentionally; by mistake
Example
She inadvertently deleted the important file while cleaning her computer.
彼女はコンピュータを掃除しているとき、重要なファイルをうっかり削除してしまった。
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 /ɪnˈdʌktɪv/

inductive

帰納的
Meaning
characterized by the inference of general laws from particular instances; reasoning from specific cases to general principles
Example
The scientist used inductive reasoning to form a hypothesis.
科学者は帰納的推論を使って仮説を立てました。
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 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。
C1 adjective /ˌɪnkənˈsɪdərət/

inconsiderate

思いやりがない
Meaning
Thoughtless; showing a lack of concern for others.
Example
It was inconsiderate of him to play loud music late at night.
夜遅くに大きな音で音楽を流すことは、思いやりがない行動でした。
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。
C1 noun /ˌɪntərˌɒpərəˈbɪləti/

interoperability

相互運用性
Meaning
The ability of computer systems or software to exchange and make use of information.
Example
The interoperability of different software systems ensures seamless workflow.
異なるソフトウェアシステムの相互運用性は、シームレスな作業の流れを確保します。
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 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 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 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 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 ɪmˈpɛə(r)mənt

impairment

損傷、障害
Meaning
The state of being damaged or weakened; a disability or handicap.
Example
Hearing impairment can be caused by long-term exposure to loud noise.
聴力障害は長期間の大きな音への曝露によって引き起こされる可能性があります。
C1 adjective /ˈɪmpjəd(ə)nt/

impudent

無礼な、厚かましい
Meaning
not showing due respect for another person; rude
Example
The impudent child talked back to the teacher.
その無礼な子供は先生に逆らった。
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 adjective /ɪnˈflæməˌtɔːri/

inflammatory

幸せ
Meaning
causing inflammation in the body; arousing anger, hostility, or strong emotion
Example
His inflammatory speech triggered protests across the city.
彼女は賞を受け取ったとき、幸せそうな表情を隠せなかった。
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 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 adjective /ˌɪməˈtɪəriəl/

immaterial

無関係
Meaning
Not important or relevant; lacking physical substance.
Example
The judge ruled that the argument was immaterial to the case.
裁判官はその議論が事件に関係ないと判断しました。
C1 noun /ɪmˈpɜː.mə.nəns/

impermanence

無常
Meaning
The state or fact of lasting for only a limited period of time.
Example
The philosophy of Buddhism emphasizes the impermanence of life.
仏教の哲学は、人生の無常性を強調します。
C1 noun /ɪnˈsek.tɪ.saɪd/

Insecticide

殺虫剤
Meaning
a substance used for killing insects; a chemical pesticide that targets insects
Example
The farmer sprayed insecticide on his crops to protect them from harmful bugs.
農夫は作物を有害な虫から守るために殺虫剤を噴霧しました。
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 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 noun /ɪˈreləvəns/

irrelevance

無関係性
Meaning
the quality of not being connected to or important for a particular matter; lack of significance
Example
His long explanation only highlighted the irrelevance of the details to the main issue.
彼の長い説明は、細部が主な問題と無関係であることを強調しただけだった。
C1 noun/verb /ˈɪmprɪnt/

imprint

刻印
Meaning
A mark or impression made by pressure; to establish or fix firmly in someone's mind.
Example
The event left an indelible imprint on the city's history.
その出来事は都市の歴史に消えない刻印を残した。
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 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 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 /ɪˈmjuː.tə.bəl/

immutable

不変の
Meaning
Unchangeable, permanent, or fixed
Example
The laws of physics are considered immutable.
物理法則は不変と見なされます。
C1 adjective /ˌɪnhɒˈspɪtəbl/

inhospitable

住みにくい
Meaning
Harsh and difficult to live in; unfriendly or unwelcoming to guests.
Example
The desert is an inhospitable environment for most plants.
砂漠はほとんどの植物にとって住みにくい環境です。
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。
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/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 /ˌaɪ.di.əˈlɒdʒ.ɪ.kəl/

ideological

イデオロギー的
Meaning
Relating to or based on a system of ideas or beliefs.
Example
The two parties are divided by deep ideological differences.
二つの党は深いイデオロギー的な違いによって分裂している。
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。
C1 verb /ɪˈnɔːɡjʊreɪt/

inaugurate

Meaning
To formally begin or introduce something, especially with a ceremony.
Example
The mayor will inaugurate the new bridge tomorrow.
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 adjective /ɪnˈdetɪd/

Indebted

借金がある; 感謝している
Meaning
owing money or gratitude to someone; obligated; grateful
Example
I am deeply indebted to my teacher for all her guidance.
私は先生のすべての指導に深く感謝しています。
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。
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 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 /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 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 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 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 /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 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 /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 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 ˌɪn.təˈdɪs.ɪ.plɪ.nər.i

interdisciplinary

学際的
Meaning
Relating to more than one branch of knowledge.
Example
The interdisciplinary approach in education enhances problem-solving skills.
教育における学際的アプローチは、問題解決スキルを向上させる。
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 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 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 noun ˌɪnsjʊˈleɪʃən

insulation

絶縁
Meaning
Material used to prevent heat, sound, or electricity from being transmitted from one area to another.
Example
Insulation of food storage areas can prevent pests from entering.
食品保管エリアの絶縁は、害虫が侵入するのを防ぐことができます。
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 /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 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 /ˌɪnklɪˈneɪʃən/

inclination

傾向
Meaning
A natural tendency or urge to act or feel in a particular way.
Example
She has an inclination towards helping others.
彼女は他の人を助ける傾向があります。
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 /ɪnˈsɪdiəs/

insidious

陰険な
Meaning
Proceeding in a gradual, subtle way but with harmful effects.
Example
The insidious spread of misinformation can damage trust.
誤った情報の陰険な広がりは信頼を傷つける可能性がある。
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 adjective /ɪnˈtræk.tə.bəl/

intractable

管理不能
Meaning
Difficult or impossible to manage, control, or solve.
Example
The conflict has become an intractable problem.
その対立は管理不能な問題になった。
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 verb /ɪɡˈnaɪt/

ignite

点火する
Meaning
To catch fire or cause to catch fire; to start or arouse.
Example
The sparks ignited the dry leaves in seconds.
火花が数秒で乾燥した葉に火をつけた。
C1 noun /ɪnˈdem.nə.ti/

Indemnity

補償
Meaning
security or protection against a loss or other financial burden; compensation for damage or loss
Example
The insurance company provided full indemnity for the damages caused by the flood.
保険会社は洪水による損害に対して完全な補償を提供しました。
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 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 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 /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 /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 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 /ɪnˈsɜːʃən/

insertion

挿入
Meaning
the action of inserting something into something else
Example
The insertion of the new data was completed successfully.
新しいデータの挿入は成功裏に完了しました。
C1 noun /ɪnˈsɒm.ni.ə/

Insomnia

不眠症
Meaning
habitual sleeplessness; inability to sleep; the condition of being unable to sleep
Example
Her chronic insomnia made it difficult for her to concentrate during work hours.
彼女の慢性的な不眠症は、仕事中に集中するのを難しくさせた。
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 verb ɪˈnɔː.ɡjə.reɪ.tɪd

inaugurated

開会
Meaning
Begin or introduce (a system, policy, or period) formally.
Example
The organization was inaugurated officially.
その組織は正式に開会されました。
C1 adjective /ɪnˈsɛnsəbl/

insensible

無意識
Meaning
Unconscious; unaware of or indifferent to something.
Example
He was insensible to the cold as he lay in the snow.
彼は雪の中で横たわっているとき、寒さに無意識でした。
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 /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 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 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 /ɪˈledʒ.ə.bəl/

illegible

読めない
Meaning
Not clear enough to be read; unreadable.
Example
The doctor’s handwriting was almost illegible.
医者の手書きはほとんど読めなかった。
C1 noun ˌɪndɪˈspensəbl̩ ˈkɒmpɪtənsi

indispensable competency

不可欠な能力
Meaning
Essential skill or ability that cannot be done without; a crucial capability that is absolutely necessary.
Example
Digital literacy is an indispensable competency in the 21st century.
デジタルリテラシーは21世紀のインディスペンセブルなコンピテンスです。
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 /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 /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 /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 /ɪnˈkɒŋɡruəs/

incongruous

不調和
Meaning
Not fitting in with or suitable for the surroundings.
Example
His jokes were incongruous during the serious meeting.
彼の冗談は真面目な会議では不調和だった。
C1 noun ˌɪnˈsaɪtfʊlnɪs

insightfulness

洞察力、分析能力
Meaning
The capacity to gain an accurate and deep intuitive understanding of a person or thing.
Example
His insightfulness helped solve the complex problem.
彼の洞察力は複雑な問題を解決するのに役立ちました。
C1 verb /ɪmˈpiːtʃ/

impeach

Meaning
To charge a public official with misconduct while in office.
Example
The parliament voted to impeach the president.
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 /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。
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 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 /ɪmˈpʌlsɪv/

impulsive

衝動的な, 直感的な
Meaning
acting suddenly without careful thought
Example
She made an impulsive decision to buy the car.
彼女は衝動的な決定で車を買うことにしました。
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 adjective /aɪˈreɪt/

irate

激怒した
Meaning
Extremely angry.
Example
The customer became irate after waiting for hours.
顧客は何時間も待った後、激怒しました。
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。