investigation
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B1 noun /ɪnˌvɛs.tɪˈɡeɪ.ʃən/

investigation

調査
Meaning
the process of inquiring into or examining something carefully to find the truth
Example
The investigation revealed new evidence about the fraud.
調査は詐欺に関する新しい証拠を明らかにしました。
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。
C2 noun /aɪˈkɒnəklæst/

iconoclast

偶像破壊者
Meaning
A person who attacks or criticizes cherished beliefs, traditions, or institutions.
Example
He was known as an iconoclast who challenged old traditions.
彼は古い伝統に挑戦した偶像破壊者として知られていました。
B2 adjective /ɪmˈpɜːrfɪkt/

imperfect

不完全
Meaning
Not perfect; having faults or flaws.
Example
The painting was beautiful despite being imperfect.
その絵は美しかったが、完璧ではなかった。
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 /ˌɪntərˈmiːdiˌɛri/

intermediary

仲介者
Meaning
A person who acts as a link between people in order to try to bring about an agreement; a mediator.
Example
The diplomat served as an intermediary between the two conflicting nations.
外交官は二つの対立する国々の間で仲介者として機能した。
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。
B2 adjective /ɪˈreɡjələr/

irregular

不規則な
Meaning
not even or consistent in shape, pattern, time, or behavior; not following normal rules
Example
His attendance at work has been irregular this month.
今月、彼の出勤は不規則だった。
C1 noun /ˈɪrɪtənt/

irritant

刺激物
Meaning
something that causes irritation or discomfort
Example
Dust is a common irritant for people with allergies.
ほこりはアレルギーを持つ人々にとって一般的な刺激物です。
B2 noun ɪˈmjuː.nɪ.ti

immunity

免疫力
Meaning
The ability of an organism to resist a particular infection or toxin by the action of specific antibodies.
Example
A strong immunity protects against infections.
強い免疫力は感染症から守ります。
B2 adjective /ɪmˈper.ə.tɪv/

imperative

命令形
Meaning
Of vital importance; crucial; giving or expressing a command.
Example
It is imperative to address the climate crisis immediately.
気候危機に直ちに対処することがインペラティブです。
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。
C2 noun /ˈɪntərˌloʊpər/

interloper

干渉者
Meaning
A person who becomes involved in a situation or place where they are not wanted.
Example
He felt like an interloper at the private family gathering.
彼はプライベートな家族の集まりで干渉者のように感じた。
C2 adjective/noun /ɪnˈkɑːrnədiːn/

incarnadine

深紅
Meaning
a bright crimson or pinkish-red color
Example
The sky turned incarnadine at sunset.
太陽が沈むと空は深紅色に変わった。
C2 noun /ɪnˈtɜːrmənt/

interment

埋葬
Meaning
The act of burying a dead body in a grave or tomb.
Example
The interment took place at the family cemetery.
埋葬は家族の墓地で行われました。
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。
A2 noun/verb /ˈɪntrəst/ or /ˈɪntəˌrɛst/

interest

興味 / 利子
Meaning
A feeling of curiosity or concern about something; or money paid for the use of borrowed money.
Example
He showed great interest in learning new languages.
彼は新しい言語を学ぶことに大きな興味を示しました。
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。
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。
C1 verb /ɪmˈpɛl/

impel

Meaning
to drive, force, or urge someone to do something
Example
Her curiosity impelled her to open the mysterious box.
C2 noun /ˌɪn.trəˈɡreʃ.ən/

introgression

遺伝子流入
Meaning
The transfer of genetic information from one species to another through repeated backcrossing.
Example
Introgression plays a significant role in plant breeding.
イントログレッションは植物育種において重要な役割を果たします。
B2 noun ɪnˈfleɪʃən

inflation

インフレーション
Meaning
A general increase in prices and fall in the purchasing value of money.
Example
Inflation erodes the purchasing power of consumers.
インフレーションは消費者の購買力を減少させる。
B1 verb /ɪmˈprɛs/

impress

感動させる
Meaning
to cause someone to feel admiration or respect
Example
Her speech managed to impress the audience.
彼女のスピーチは聴衆を感動させました。
B2 verb /ɪˈnɪʃieɪt/

initiate

開始する
Meaning
to begin or start; to introduce someone to a new activity
Example
The company will initiate a new training program.
会社は新しい研修プログラムを開始します。
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 /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。
B2 adjective ˈaɪsəˌleɪtɪd

isolated

孤立した
Meaning
Alone or separated from others; having little or no contact with other people.
Example
Technological advancements often leave people isolated.
技術の進歩はしばしば人々を孤立させる。
A1 pronoun /aɪ/

i

Meaning
used by a speaker to refer to himself or herself
Example
I am learning English every day.
私は毎日英語を学んでいます。
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。
B2 noun /ɪnˈfek.ʃən/

Infection

感染
Meaning
the process of infecting or the state of being infected; a disease caused by germs
Example
The doctor prescribed antibiotics to treat the bacterial infection in her throat.
医師は彼女の喉の細菌感染を治療するために抗生物質を処方しました。
C2 adjective /ˌɪrɪˈkɒnsɪləbl/

irreconcilable

和解できない
Meaning
impossible to make compatible or bring into harmony; unable to resolve differences
Example
The couple separated due to irreconcilable differences.
そのカップルは和解できない違いのために別れました。
B2 adjective /ɪnˈstrʌkʃənəl/

instructional

教育的な
Meaning
providing knowledge or information; intended to teach
Example
The website offers many instructional videos for beginners.
このウェブサイトは初心者向けに多くの教育的なビデオを提供しています。
C1 verb /ˈɪmprəvaɪz/

improvise

Meaning
To create or perform something spontaneously without preparation.
Example
The actor had to improvise his lines when he forgot the script.
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 adverb /ɪnˈvɜːrs.li/

Inversely

逆に; 反対に
Meaning
in a way that is opposite or contrary; in reverse order or manner
Example
The price of goods is inversely related to their availability in the market.
商品の価格は市場での入手可能性に逆に関連しています。
C2 adjective /ˈɪm.pi.əs/

Impious

不敬な; 冒涜的
Meaning
irreligious; lacking reverence for religion; blasphemous
Example
The impious act shocked the religious community.
不敬な行為は宗教コミュニティを驚かせました。
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。
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 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。
C1 adjective /ɪnˈtɛlɪdʒəbl/

intelligible

Meaning
Able to be understood; clear enough to be comprehended.
Example
Her speech was barely intelligible over the noise.
C2 adjective /ɪnˈɡreɪʃiˌeɪtɪŋ/

ingratiating

お世辞を言う
Meaning
Charming or flattering in a way intended to gain favor.
Example
His ingratiating smile made everyone trust him quickly.
彼のお世辞を言う笑顔は、すべての人々に彼を素早く信頼させた。
C2 noun /ˈaɪdɪl/

idyll

田園詩的なシーン
Meaning
An extremely happy, peaceful, or picturesque episode or scene, often idealized.
Example
Their honeymoon was an idyll on a tropical island.
彼らのハネムーンは熱帯の島での田園詩的なシーンでした。
C1 noun /ˈɪnkjʊˌbeɪtər/

incubator

インキュベーター
Meaning
a device or environment that provides suitable conditions for eggs, cells, or infants to develop
Example
The premature baby was placed in an incubator for care.
未熟児はケアのためにインキュベーターに入れられました。
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 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 verb /ɪnˈsɪnjueɪt/

insinuate

Meaning
To suggest or hint something indirectly and often unpleasantly.
Example
He insinuated that she had lied about her qualifications.
C1 adjective /ɪˈnɔːɡjərəl/

Inaugural

開幕
Meaning
marking the beginning of something; first; opening
Example
The president delivered his inaugural speech.
大統領は彼の開幕スピーチを行いました。
C2 adjective /ˌɪn.trəˈmjʊə.rəl/

intramural

学内
Meaning
Occurring within the walls of a single institution, especially a school or college.
Example
The college organizes intramural sports competitions every semester.
大学は毎学期、学内スポーツ競技を開催しています。
C2 noun /ˌɪnsəˈrɛkʃən/

insurrection

反乱
Meaning
A violent uprising against an authority or government.
Example
The army was called in to suppress the insurrection.
軍隊は反乱を鎮圧するために呼ばれました。
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 adjective /ˌɪnsɪˈdɛntəl/

incidental

付随的
Meaning
happening as a minor part or in connection with something else
Example
Incidental expenses like snacks and tips were included in the bill.
スナックやチップのような付随的な費用は請求書に含まれていました。
A2 noun/verb /ˈaɪən/ or /ˈaɪərn/

iron

鉄 / アイロン
Meaning
a strong, hard metal used in construction; also to press clothes with heat
Example
He used an iron to smooth his shirt.
彼はシャツを滑らかにするためにアイロンを使った。
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。
B2 adjective ɪˈmɜː.sɪv

immersive

没入型
Meaning
Providing, involving, or characterized by deep absorption or immersion in something.
Example
Virtual reality creates an immersive learning environment.
仮想現実は没入型の学習環境を作り出します。
C1 verb /ɪˈmɔːrtəlaɪz/

immortalize

不朽の
Meaning
to preserve the memory of someone or something forever
Example
The statue was built to immortalize the hero’s sacrifice.
その像は、英雄の犠牲を永遠にするために建てられました。
B2 adjective /ˌɪnstɪˈtjuːʃənl/

institutional

制度的
Meaning
Relating to an organization or established practice.
Example
The government made several institutional reforms in education.
政府は教育においていくつかの制度的改革を実施しました。
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。
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 noun /ɪkˈsɔːr.ə/

Ixora

イクソラ
Meaning
a tropical flowering shrub with clusters of small bright red, orange, or yellow flowers
Example
The bright red ixora bushes lined the pathway to the tropical garden.
明るい赤いイクソラの低木が熱帯庭園への小道を囲んでいました。
B2 noun ˈɪn.frəˌstrʌk.tʃər

infrastructure

インフラストラクチャー
Meaning
The basic physical and organizational structures and facilities needed for the operation of a society or enterprise.
Example
Digital infrastructure is vital for future advancements.
デジタルインフラストラクチャーは将来の進歩にとって不可欠です。
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。
C1 adjective /ˌɪndɪˈstɪŋkt/

indistinct

不明瞭な
Meaning
Not clear or sharply defined; vague or blurred.
Example
The sound of voices was indistinct in the distance.
遠くからの声は不明瞭でした。
B2 adjective /ˈɪmɪnənt/

imminent

差し迫った
Meaning
About to happen; likely to occur very soon.
Example
Dark clouds signaled that a storm was imminent.
暗い雲は嵐が迫っていることを示していた。
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。
B2 verb /ɪmˈplaɪ/

imply

暗示する
Meaning
To suggest something without directly stating it.
Example
Her tone seemed to imply that she was upset.
彼女の口調は、彼女が怒っていることを示唆しているようでした。
B1 verb /ɪnˈvɛs.tɪ.ɡeɪt/

investigate

調査する
Meaning
to carry out a systematic inquiry to discover facts or information
Example
The police will investigate the incident thoroughly.
警察は事件を徹底的に調査するでしょう。
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 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。
C1 noun /ɪnˈfɜːrnoʊ/

inferno

火災
Meaning
a large, intense fire that is dangerously out of control
Example
The building turned into an inferno within minutes.
その建物は数分で火災に変わった。
B2 adjective /ɪˈmjuːn/

immune

免疫の
Meaning
protected from disease or from the effects of something
Example
Children who are vaccinated are immune to many diseases.
予防接種を受けた子供たちは多くの病気に免疫があります。
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。
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。
B2 noun /ɪmˈpeɪʃəns/

impatience

忍耐力不足
Meaning
The state of being quickly irritated or unable to wait calmly.
Example
His impatience grew as the meeting dragged on.
会議が長引くにつれて、彼の忍耐力不足が増しました。
B1 noun /ɪnˈstrʌkʃən/

instruction

指示
Meaning
Detailed information telling how something should be done or operated.
Example
Please read the instruction carefully before using the machine.
機械を使用する前に指示をよく読んでください。
A2 noun /ɪmˈpɔːtəns/

importance

重要性
Meaning
The quality or state of being important; consequence or significance.
Example
The importance of time management cannot be overstated.
タイムマネジメントの重要性は過大評価できません。
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 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。
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。
A1 preposition /ˈɪntuː/

into

中へ
Meaning
expressing movement or direction to the inside of something
Example
She walked into the room quietly.
彼女は静かに部屋に入った。
C1 noun /ˈɪmɪnəns/

imminence

差し迫り、間近な状態
Meaning
the state of being about to happen
Example
The imminence of the storm forced people to take shelter.
嵐の差し迫りが人々を避難させることを強制した。
B2 noun /ɪnˈtɛnt/

intent

意図
Meaning
the purpose or reason behind an action; a strong determination to do something
Example
Her intent was to improve the quality of education in the community.
彼女の意図はコミュニティの教育の質を向上させることでした。
A2 noun /ˈaɪ.lənd/

Island

Meaning
a piece of land completely surrounded by water
Example
We visited a beautiful island during our vacation.
私たちは休暇中に美しい島を訪れました。
B1 adjective /ɪnˈtɜːrnəl/

internal

内部
Meaning
situated inside; relating to the inside or inner part of something
Example
The company is conducting an internal audit this month.
その会社は今月内部監査を行っています。
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 noun ɪnˈdʌldʒəns

indulgence

嗜好
Meaning
The practice of allowing oneself to enjoy the pleasure of something.
Example
His indulgence in junk food affected his health.
彼のジャンクフードへの過度の嗜好は健康を害した。
C1 adjective /ɪnˈhjuːmən/

Inhuman

非人道的
Meaning
lacking human qualities of compassion and mercy; cruel or barbaric
Example
The prisoners were kept in inhuman conditions.
囚人たちは非人道的な状況で収容されていました。
C2 adjective /ɪˈlɪmɪtəbl/

illimitable

無限
Meaning
Without limits or bounds.
Example
The universe is often described as illimitable.
宇宙はしばしば無限であると説明されます。
B1 verb /ɪnˈtend/

intend

意図する
Meaning
to plan or have in mind as a purpose; to mean
Example
I intend to finish this project by tomorrow.
私はこのプロジェクトを明日までに終わらせるつもりです。
C2 noun /ˌɪnkrʌˈsteɪʃən/

incrustation

硬化層
Meaning
a crust or hard coating formed on the surface of something
Example
The old pipes were blocked due to heavy incrustation of minerals.
古いパイプは鉱物の重い硬化層によって詰まっていました。
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。
B2 adjective /ɪmˈpɪəriəl/

imperial

帝国の
Meaning
Relating to an empire or emperor; having supreme authority.
Example
The imperial palace was a symbol of the emperor's power.
インペリアル宮殿は皇帝の力の象徴でした。
B2 noun /ɪnˈsen.tɪv/

Incentive

インセンティブ; 刺激
Meaning
a thing that motivates or encourages someone to do something; a reward or penalty that influences behavior
Example
The company offered a cash incentive to employees who exceeded their sales targets.
その会社は売上目標を達成した従業員に現金インセンティブを提供しました。
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 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。
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 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。
C1 adjective /ˌɪrɪˈprɛsəbl̩/

irrepressible

抑制できない
Meaning
Impossible to control or restrain.
Example
She had an irrepressible urge to laugh during the speech.
彼女はスピーチ中に抑制できない笑いの衝動を隠すことができませんでした。
C2 adjective /ɪmˈprɒvɪdənt/

improvident

先見の明がない
Meaning
Not having or showing foresight; spending wastefully or without thought for the future.
Example
His improvident habits left him with no savings.
彼の先見の明がない習慣は、貯金がないまま彼を残した。
C2 adjective /ˌɪnkɒntrəˈvɜːtəbl/

incontrovertible

論争の余地がない
Meaning
impossible to deny or dispute; unquestionable
Example
The evidence was incontrovertible and proved his innocence.
その証拠は論争の余地がなく、彼の無罪を証明しました。
C1 verb /ɪnˈkrɪmɪˌneɪt/

incriminate

有罪にする
Meaning
to make someone appear guilty of a crime or wrongdoing
Example
The new evidence could incriminate the suspect in the robbery case.
新しい証拠がロビー事件の容疑者を有罪にする可能性があります。
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。
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。
B2 verb /ˈɪl.ə.streɪt/

illustrate

説明する
Meaning
to explain or make something clear by using examples, pictures, or comparisons
Example
The teacher used diagrams to illustrate the concept.
先生はその概念を説明するために図を使いました。
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 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。
B1 noun ɪnˈvestmənt

investment

投資
Meaning
The action or process of investing money for profit or material result.
Example
Investment in waste management infrastructure is essential.
廃棄物管理インフラへの投資は不可欠です。
A1 adjective /ˈɪntrəstɪŋ/ or /ˈɪntəˌrɛstɪŋ/

interesting

面白い
Meaning
Arousing curiosity or attention; holding one’s interest.
Example
The documentary about space was very interesting.
宇宙についてのドキュメンタリーはとても面白かった。
C1 adjective /ɪnˈvɑːlənˌtɛri/

involuntary

不随意
Meaning
done without will or conscious control
Example
He gave an involuntary shiver when he heard the loud noise.
彼は大きな音を聞いたとき、不随意に震えた。
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。
A2 noun /ˈɪlnəs/

illness

病気
Meaning
A condition of being unwell or suffering from a disease.
Example
She missed school due to a serious illness.
彼女は深刻な病気のため学校を休んだ。
C1 adjective /ɪmˈpæsəbəl/

impassable

通行不可能
Meaning
Impossible to travel along or over.
Example
The road became impassable after the heavy snowfall.
大雪の後、道は通行不可能になりました。
C1 noun /ˈɪn.tə.mə.si/

Intimacy

親密さ; 親しみ
Meaning
close familiarity or friendship; closeness; a private cozy atmosphere
Example
The couple valued the emotional intimacy they shared more than material possessions.
そのカップルは物質的な所有物よりも、共有した感情的な親密さを大切にしていました。
C1 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 ɪnˈtrɪn.zɪk

intrinsic

内在的, 本質的, 自然な
Meaning
Belonging naturally; essential. Existing as a natural or basic part of something.
Example
Creativity is an intrinsic quality of a great artist.
創造性は偉大なアーティストの内在的な資質です。
B2 noun /ˌɪmɪˈɡreɪʃən/

immigration

移民
Meaning
the action of coming to live permanently in a foreign country
Example
Immigration policies vary from country to country.
移民政策は国によって異なります。
B1 noun ˌɪndɪˈpendəns

independence

独立
Meaning
The fact or state of being independent; freedom from outside control; not being subject to another's authority.
Example
Independence inspired the movement.
独立は運動を刺激した。
B2 verb /ɪnˈtɜːrprət/

interpret

Meaning
to explain the meaning of something; to translate orally
Example
She had to interpret the speech for the foreign guests.
B2 adjective /ɪnˈtɒlərənt/

intolerant

不寛容
Meaning
unwilling to accept or respect beliefs or behavior different from one's own
Example
He is intolerant of any opinion that differs from his own.
彼は自分の意見と異なる意見を全く容認しません。
B2 adjective ɪnˈev.ɪ.tə.bəl

inevitable

避けられない
Meaning
Certain to happen; unavoidable.
Example
Death is an inevitable part of life.
死は人生の避けられない一部です。
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。
C2 noun /ˌɪnjuːˈɛndəʊ/

innuendo

暗示
Meaning
An allusive or oblique remark or hint, typically a suggestive or disparaging one.
Example
The manager's innuendo was directed towards his competitor.
マネージャーの暗示は競争相手に向けられていました。