unimportance
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C1 noun /ʌnɪmˈpɔːrtəns/

unimportance

重要でなさ
Meaning
the state or quality of being insignificant or not important
Example
He dismissed the issue with a sense of unimportance.
彼はその問題を重要でないものとして無視した。
B2 verb /ʌnˈfəʊld/

unfold

広げるまたは開く
Meaning
to open or spread out something that was folded; to gradually reveal or develop
Example
She unfolded the letter carefully.
彼女は手紙を慎重に広げました。
B2 adjective /ʌnfəˈmɪl.jər/

Unfamiliar

不明な; 見知らぬ
Meaning
not known or recognized; strange
Example
The city was unfamiliar to me since I had never been there before.
その都市は私にとって見知らぬ場所でした。なぜなら、私はそこに行ったことがなかったからです。
B1 adjective /ʌnˈwɒn.tɪd/

Unwanted

望まれない
Meaning
not desired or welcome; not wanted
Example
He felt like an unwanted guest at the meeting.
彼は会議で望まれない客のように感じた。
C2 noun /ˌjuːnɪˈtɛəriən/

unitarian

ユニタリアン
Meaning
A person who believes that God exists as one entity rather than as a Trinity; a member of a religious denomination that emphasizes individual freedom of belief.
Example
The Unitarian church is known for its inclusive and open-minded approach.
ユニタリアン教会は、その包括的で開かれた考え方で知られています。
B1 noun /ˈjuːnɪvɜːrs/

Universe

宇宙
Meaning
all existing matter and space; the cosmos
Example
Scientists study the universe to understand its mysteries.
科学者たちは宇宙の謎を解明するために研究しています。
B2 adjective /ʌnˈriːzənəbəl/

unreasonable

理不尽な
Meaning
not guided by reason or fairness; excessive or extreme beyond what is acceptable
Example
The manager made an unreasonable demand that no one could realistically meet.
マネージャーは理不尽な要求をした。
A2 adjective /ʌnˈlʌki/

Unlucky

不運; ラッキーでない
Meaning
having bad luck; unfortunate
Example
He was unlucky to miss the winning shot.
彼は勝つシュートを外して不運だった。
B1 adverb /ˌʌpsaɪd ˈdaʊn/

Upside-down

逆さま
Meaning
with the upper part at the bottom; in or into a reversed position
Example
The picture was hanging upside-down on the wall.
絵は壁に逆さまに掛かっていた。
C2 noun /ɜːrˈbænɪti/

urbanity

都会的な気品
Meaning
refined courtesy, elegance, and sophistication in manner
Example
Her urbanity made her popular among diplomats and leaders.
彼女の都会的な気品は、外交官やリーダーの間で人気を集めました。
B2 verb ˈjuːnɪfaɪ

unify

統一する
Meaning
To make or become united, uniform, or whole; to bring together into a single unit.
Example
Adolescents unify with peers for social acceptance.
若者たちは社会的受け入れのために仲間と統一します。
A1 preposition/conjunction /ʌnˈtɪl/

until

まで
Meaning
up to the time of
Example
I will wait until you come back.
私はあなたが戻るまで待ちます。
C1 noun /ˌʌnbɪˈliːf/

Unbelief

不信
Meaning
lack of religious belief; skepticism or doubt
Example
His unbelief in the supernatural made him a skeptic.
超自然に対する彼の不信は彼を懐疑的にしました。
C1 verb /ʌnˈroʊl/

unroll

広げる
Meaning
to open something that is rolled up; to spread out gradually
Example
She unrolled the map on the table to find the route.
彼女は道を探すためにテーブルの上で地図を広げた。
A2 adjective /ʌnˈhel.θi/

Unhealthy

不健康な; 健康に悪い
Meaning
harmful to health; not in good health; detrimental to well-being
Example
Eating too much fast food is unhealthy for your body.
ファーストフードを食べ過ぎることは、あなたの体に不健康です。
B2 adjective /juːˈnæn.ɪ.məs/

Unanimous

全会一致
Meaning
fully in agreement; shared by all
Example
The committee reached a unanimous decision.
委員会は全会一致の決定を下しました。
C1 noun /juːˈtoʊpiə/

utopia

ユートピア
Meaning
An imagined perfect society or place where everything is ideal.
Example
Many philosophers dreamed of creating a utopia for humanity.
多くの哲学者は人類のためにユートピアを作る夢を見ていました。
A2 noun /ˌʌndərˈstændɪŋ/

understanding

理解
Meaning
the ability to grasp the meaning, significance, or nature of something
Example
Her understanding of the issue was impressive.
彼女の問題に対する理解は印象的でした。
A2 noun /ˈʌndərwɛr/

Under wear

下着
Meaning
clothing worn under other clothes, next to the skin
Example
She bought new underwear from the department store.
彼女はデパートで新しい下着を買いました。
B2 adjective /ʌnˈkwɒl.ɪ.faɪd/

Unqualified

資格がない; 経験不足の;
Meaning
not having the necessary skills or qualifications; complete or absolute
Example
He was unqualified for the engineering position due to lack of experience.
彼は経験不足でエンジニアの職に不適格でした。
C1 adjective /ˌʌnˈɪntɪmeɪtɪŋ/

unintimating

示唆しない
Meaning
Not giving a hint or suggestion; not indicating.
Example
His unintimating tone gave no clue of his true feelings.
彼の示唆しない口調は彼の本当の気持ちを示すものではありませんでした。
C1 verb /ˈʌndərkʌt/

undercut

Meaning
to sell at a lower price than a competitor; to weaken or undermine something
Example
The company tried to undercut its rivals by offering lower prices.
C2 adjective /ʌkˈsɔːriəs/

uxorious

妻に対して過度に愛情深い
Meaning
excessively fond of or submissive to one's wife
Example
He was so uxorious that he agreed with everything his wife said.
彼は妻に対してそれほどまでに uxorious で、妻が言ったことすべてに同意しました。
B1 adjective /ʌnˈkaɪnd/

Unkind

無愛想; 不親切
Meaning
cruel; not nice or caring toward others
Example
It was unkind of him to make fun of her appearance.
彼が彼女の外見をからかうのは不親切だった。
C2 adjective /ʌnəˈpiːzd/

unappeased

満足していない
Meaning
Not satisfied or calmed; still feeling discontent or anger
Example
Despite the apology, she remained unappeased.
謝罪にもかかわらず、彼女は満足していなかった。
B2 adverb /ˈɜːrdʒəntli/

urgently

緊急に
Meaning
in a way that requires immediate attention or action
Example
The patient urgently needs medical attention.
患者は緊急に医療処置が必要です。
C1 adjective ʌnɪnˈhæbɪtəbəl

uninhabitable

住めない
Meaning
Not suitable or safe for people to live in.
Example
Rapid urbanization can make cities uninhabitable.
急速な都市化は都市を住めない場所にする可能性があります。
C2 adjective /ˌʌn.təˈwɔːrd/

untoward

予期しない
Meaning
Unexpected and inappropriate or inconvenient.
Example
The meeting ended without any untoward incidents.
会議は予期しない事件なしで終了しました。
B2 adjective /ʌnˈstɛdi/

unsteady

不安定な
Meaning
not firm or stable; likely to change or fail
Example
She felt unsteady on her feet after the long journey.
長旅の後、彼女は足元が不安定だった。
B2 adjective /ʌnˈfeɪθ.fəl/

Unfaithful

不忠実
Meaning
not loyal or true to a spouse, partner, or commitment
Example
He was unfaithful to his wife for many years.
彼は何年も妻に不忠実でした。
B1 adjective /ʌnˈpɒpjʊlə/

unpopular

不人気な
Meaning
not liked or supported by many people
Example
The decision was unpopular with the public.
その決定は世間で不人気だった。
C1 adjective /ˌʌnəkˈnɒlɪdʒd/

unacknowledged

認められない
Meaning
Not recognized, admitted, or accepted; ignored or unnoticed
Example
Her contributions to the project went unacknowledged.
彼女のプロジェクトへの貢献は認められなかった。
C2 adjective /ˈʌndjʊləs/

undulous

波打つ
Meaning
Having a wavy surface or form.
Example
The artist painted the undulous sea at sunset.
アーティストは夕日に照らされた波打つ海を描きました。
C1 adjective /ʌnˈɜːrθli/

unearthly

超自然的
Meaning
Strange or unnatural in a way that seems not of this world
Example
The forest was filled with an unearthly glow.
森は超自然的な輝きで満たされていました。
C1 noun ˌʌndərˈprɪvəlɪdʒd ɡruːps

underprivileged groups

恵まれないグループ
Meaning
Groups of people who lack basic necessities or advantages that are available to other members of society.
Example
Underprivileged groups benefit from social initiatives.
恵まれないグループは社会的なイニシアティブから利益を得ます。
C1 adjective /ʌnˈsɪvəlaɪzd/

Uncivilized

未開の; 野蛮な;
Meaning
not developed in terms of civilization; lacking social organization and culture; barbarous
Example
The explorers encountered an uncivilized tribe deep in the Amazon rainforest.
探検家たちはアマゾンの雨林の奥深くで未開の部族に出会った。
B2 adjective /ˌʌnkənˈtroʊld/

uncontrolled

制御不能な
Meaning
not restrained or managed; lacking control
Example
The wildfire spread in an uncontrolled manner, causing widespread damage.
山火事は制御不能な方法で広がり、広範囲に被害をもたらした。
C1 adjective /ˌʌnprɪˈtɛnʃəs/

unpretentious

控えめな
Meaning
modest; not attempting to impress others with appearance or importance
Example
She lives in an unpretentious home but is very happy.
彼女は控えめな家に住んでいますが、とても幸せです。
B1 adverb /ʌnˈjuːʒuəli/

unusually

異常に
Meaning
in a way that is not typical or expected; to an uncommon degree
Example
It was unusually cold for this time of year.
この時期にしては異常に寒かった。
B2 adjective /ʌnˈbiːtən/

Unbeaten

負けなし; 敗北なし
Meaning
not defeated; having never lost; undefeated
Example
The team remains unbeaten this season.
そのチームは今シーズン無敗です。
B2 adjective /ʌnˈθɪŋkəbl/

Unthinkable

想像を絶する
Meaning
impossible to conceive or imagine; beyond belief or consideration
Example
It was unthinkable that such a tragedy could happen in our peaceful town.
私たちの平和な街でそのような悲劇が起こるなんて、想像を絶していました。
C1 adjective /ˌʌndərˈsaɪzd/

undersized

小さすぎる
Meaning
Smaller than the usual or expected size.
Example
The undersized puppy struggled to keep up with its siblings.
小さすぎる子犬は、兄弟姉妹と一緒に歩くのに苦労しました。
C1 verb /ʌnˈrævəl/

unravel

Meaning
To undo twisted or knitted threads; to solve or explain something complicated.
Example
The detective worked hard to unravel the mystery.
B1 noun /juːˈten.səlz/

Utensils

食器
Meaning
tools or implements used for cooking, eating, or serving food
Example
Please wash all the cooking utensils after preparing dinner.
ディナーを準備した後、すべての料理用具を洗ってください。
B2 adjective /ˌʌndɪˈstɜːrbd/

Undisturbed

邪魔されない
Meaning
not interrupted or interfered with; calm and peaceful
Example
She slept undisturbed for eight hours.
彼女は8時間、邪魔されずに眠った。
C1 noun /ʌpˈhiːvəl/

upheaval

激変
Meaning
a violent or sudden change or disruption to something
Example
The company faced a major upheaval after the sudden resignation of its CEO.
その会社は、CEOの突然の辞任後、大きな激変を経験しました。
C1 adjective /ʌnˈʃeɪkən/

Unshaken

動揺しない; 固い
Meaning
not disturbed or affected; firm and steady; unwavering
Example
Her faith remained unshaken despite all the challenges.
彼女の信念はすべての困難にも動揺しませんでした。
C1 verb /ˌʌndəˈreɪt/

underrate

過小評価
Meaning
to fail to recognize the full value or importance of something or someone
Example
Many people underrate the benefits of regular exercise.
多くの人々が定期的な運動の利点を過小評価しています。
B2 adjective /ʌnprəˈdʌk.tɪv/

Unproductive

非生産的; 効率が悪い
Meaning
not achieving much; not producing good results
Example
The meeting was unproductive and wasted everyone's time.
会議は非生産的で、全員の時間を無駄にしました。
C1 noun /ˌʌnriˈælɪti/

unreality

非現実感
Meaning
the state or quality of being unreal; lack of reality or truth
Example
The dreamlike setting gave the story a sense of unreality.
夢のような舞台は物語に非現実感を与えた。
B1 noun /ˈjuːs.fəl.nəs/

Usefulness

有用性
Meaning
the quality of being useful; practical value or helpfulness
Example
The usefulness of this tool became apparent during the project.
このツールの有用性はプロジェクト中に明らかになりました。
C1 adjective /ʌnˈvaɪəbl/

unviable

実現不可能
Meaning
Not capable of working successfully; not feasible or practical.
Example
The project was deemed unviable due to high costs.
高額なコストのため、このプロジェクトは実現不可能と見なされました。
C1 noun /ʌnˈfeɪθfʊlnəs/

unfaithfulness

不貞
Meaning
the quality of being disloyal or not faithful; breach of trust or fidelity
Example
His unfaithfulness led to the end of their marriage.
彼の不貞は結婚の終わりをもたらした。
C1 noun /ˈʌp.ʃɒt/

Upshot

結果; 結論
Meaning
the final result or outcome of a series of events; conclusion
Example
The upshot of the meeting was a decision to postpone the project.
会議の結果はプロジェクトの延期を決定することでした。
B1 noun /ˈjuːnjən/

Union

連合
Meaning
the action of joining or combining; a political unit formed from separate states
Example
The union of the two companies created a powerful corporation.
二つの企業の連携が強力な企業を作り出しました。
C2 adjective /ˌʌnɪmˈpiːtʃəbl/

unimpeachable

非難の余地がない
Meaning
Not able to be doubted, questioned, or criticized; completely trustworthy.
Example
She is known for her unimpeachable honesty.
彼女はその非難の余地がない誠実さで知られています。
B2 adjective /ʌnˈskɪld/

Unskilled

未熟な; 技術のない労働者
Meaning
lacking technical training or ability; not requiring special skills
Example
Many unskilled workers are looking for training opportunities.
多くの未熟な労働者がトレーニングの機会を探しています。
B2 adjective /ˌʌn.əkˈsep.tə.bəl/

Unacceptable

受け入れられない
Meaning
not satisfactory or allowable; not acceptable
Example
The quality of work was completely unacceptable.
仕事の質は完全に受け入れられませんでした。
C1 adjective /ʌnˈseɪvəri/

unsavory

不快
Meaning
Disagreeable, unpleasant, or morally offensive.
Example
The politician was linked to an unsavory scandal.
その政治家は不快なスキャンダルに関連していました。
C1 adjective /ʌnˈtaɪmli/

Untimely

不適切なタイミングで
Meaning
happening at an inappropriate or inconvenient time; premature
Example
His untimely death at the age of thirty shocked everyone.
彼の不適切なタイミングでの死は30歳でみんなを驚かせた。
B1 adjective /ʌnˈwel/

Unwell

体調不良; 病気
Meaning
not in good health; feeling sick or ill
Example
She has been feeling unwell since yesterday.
彼女は昨日から体調が悪い。
C1 adverb /ˌʌnkənˈvɛnʃənəli/

unconventionally

型破りに
Meaning
in a way that is not based on or conforming to accepted standards or norms
Example
She dresses unconventionally, mixing bold colors and patterns that surprise everyone.
彼女は型破りに服装をしており、大胆な色と柄を組み合わせて皆を驚かせる。
B1 adjective /ˈʌpˌkʌmɪŋ/

upcoming

今後の
Meaning
about to happen or appear
Example
The upcoming event will be held next week.
今後のイベントは来週行われます。
B2 adjective /ˌjuːnɪˈvɜːrsəl/

Universal

普遍的な
Meaning
applicable to all cases; existing everywhere
Example
Music is a universal language that everyone understands.
音楽は誰もが理解できる普遍的な言語です。
C1 adjective /ʌnˈskeɪðd/

unscathed

無傷
Meaning
Without suffering any injury, damage, or harm.
Example
She escaped from the accident unscathed.
彼女は事故から無傷で逃げ出した。
B2 noun ˌɜːbənaɪˈzeɪʃən

urbanization

都市化
Meaning
The process by which towns and cities are formed and become larger as more people begin living and working in central areas.
Example
Urbanization leads to more developed infrastructure.
都市化はより発展したインフラストラクチャーをもたらす。
C1 noun /ˌʌl.tɪˈmeɪ.təm/

Ultimatum

最終通告
Meaning
a final demand or statement of terms, the rejection of which will result in retaliation
Example
The boss gave him an ultimatum: improve or be fired.
上司は彼に最終通告を与えた：改善するか、解雇されるかだ。
B1 adjective ʌnˈplænd

unplanned

計画外の
Meaning
Not planned or arranged in advance; happening spontaneously without preparation.
Example
Unplanned urbanization contributes to environmental issues.
計画外の都市化は環境問題に寄与する。
C1 adjective /ˌjuːnɪˈsɛljʊlər/

unicellular

単細胞
Meaning
Consisting of a single cell.
Example
Amoebas are unicellular organisms.
アメーバは単細胞生物です。
B2 adverb /ʌnˈdaʊtɪdli/

undoubtedly

間違いなく
Meaning
without a doubt, certainly
Example
He is undoubtedly the best player on the team.
彼は間違いなくチームで一番の選手です。
A1 adjective /juːzd/

used

中古
Meaning
having already been used
Example
This is a used car.
これは中古車です。
B1 adjective /ʌnˈjuzd/

Unused

未使用の; 使われていない
Meaning
not being used; not having been used before
Example
There are many unused rooms in this old mansion.
この古い館には未使用の部屋がたくさんあります。
C2 adjective /ʌnˈtɛmpərd/

untempered

無調整
Meaning
not moderated or softened; lacking proper balance or control
Example
The untempered anger of the crowd caused chaos.
群衆の無調整な怒りが混乱を引き起こしました。
A2 noun /ˈjuːnɪt/

unit

ユニット
Meaning
an individual thing or person regarded as a single and complete entity
Example
Each unit in the production line is carefully tested.
生産ラインの各ユニットは慎重にテストされます。
C1 adjective /ˌʌnrɪˈkwaɪtɪd/

unrequited

Meaning
Not returned or reciprocated, especially in the context of love or affection.
Example
He suffered from unrequited love for years.
C2 adjective /ʌnˈtʃeɪst/

Unchaste

不道徳な; 不潔な;
Meaning
not celibate; having engaged in sexual relations; lacking moral purity
Example
The conservative society considered her behavior unchaste and improper.
保守的な社会は彼女の行動を不道徳で不適切だと考えた。
A1 adverb /ʌp/

up

上
Meaning
towards a higher position or level
Example
He climbed up the ladder quickly.
彼はすばやくはしごを上った。
B2 adjective /ʌnˈhɜːd/

Unheard

聞かれなかった; 未知の
Meaning
not heard or listened to; not given a hearing; unknown or unfamiliar
Example
His complaints went unheard by the management.
彼の苦情は経営陣に無視されました。
C2 adverb /ʌnˈɜːrɪŋli/

unerringly

間違いなく
Meaning
Without making any mistakes; always accurate
Example
The archer aimed unerringly at the target.
弓矢は間違いなくターゲットに向かって狙いを定めた。
B2 noun /ˈʌpˌkiːp/

up-keep

維持管理
Meaning
The process or cost of maintaining something in good condition.
Example
The upkeep of the old house is very expensive.
古い家の維持管理は非常に高価です。
B2 adverb /ˈʌltəmətli/

ultimately

最終的に
Meaning
in the end, after everything else
Example
Ultimately, we decided to go ahead with the project.
最終的に、私たちはプロジェクトを進めることに決めました。
B2 adjective /ʌnˈlɪmɪtɪd/

unlimited

無制限
Meaning
without any limits or restrictions
Example
The internet plan offers unlimited data for the whole month.
インターネットプランは1ヶ月間の無制限データを提供します。
C2 adjective /ʌnˈmɪtɪɡeɪtɪd/

unmitigated

完全な
Meaning
absolute; not lessened or moderated
Example
The meeting was an unmitigated disaster.
会議は完全な災害でした。
C1 adjective /ˌʌnəˈdɔːrnd/

unadorned

シンプルな、飾りのない
Meaning
Plain and simple; not decorated.
Example
The room was unadorned, with only a table and a chair.
部屋はシンプルで、テーブルと椅子だけがありました。
A2 adjective /ʌnˈtaɪdi/

Untidy

散らかった; 無秩序な;
Meaning
not neat or orderly; messy and disorganized
Example
Her untidy room was filled with clothes scattered everywhere.
彼女の散らかった部屋は、どこにでも散らばった服でいっぱいでした。
A1 verb /ˌʌndərˈstænd/

understand

理解する
Meaning
to know the meaning of something; to comprehend
Example
Do you understand the instructions?
指示が理解できますか?
B1 adjective /ʌnˈlaɪk/

Unlike

異なる; 類似していない
Meaning
different from; not similar to
Example
Unlike his brother, he prefers quiet activities.
彼の兄とは異なり、彼は静かな活動を好む。
B2 adjective /ʌnˈrɪəl/

unreal

非現実的な
Meaning
not real or not based on reality; exaggerated or imaginary
Example
The experience felt unreal after the sudden news.
突然の知らせの後、その体験は非現実的に感じられた。
C1 noun ˈʌp.raɪ.zɪŋ

uprising

反乱
Meaning
An act of resistance or rebellion; a revolt against an authority or government.
Example
The uprising marked the beginning of the revolution.
反乱は革命の始まりを示しました。
B1 adjective /ʌnˈplɛz.ənt/

Unpleasant

不快な
Meaning
not giving or causing pleasure; disagreeable
Example
The medicine had an unpleasant taste.
その薬は不快な味がしました。
C2 noun /ˈʌmbrɪdʒ/

umbrage

怒り, 不満
Meaning
A feeling of resentment or offense.
Example
She took umbrage at his rude remark.
彼女は彼の無礼な発言に怒りを感じた。
C2 noun /ˈʌŋkʃən/

unction

聖別
Meaning
The act of anointing as part of a religious or ceremonial ritual; excessive or insincere flattery.
Example
The priest performed the holy unction with solemnity.
司祭は厳粛に聖別の儀式を行った。
C1 adjective ˌʌn.pəˈtɜːbd

unperturbed

何かに悩まされたり、動揺したりしない; 冷静で落ち着いている
Meaning
Not worried or disturbed by something; calm and composed.
Example
She remained unperturbed despite the challenges.
彼女は挑戦にもかかわらず冷静さを保っていた。
B1 adjective /ʌnˈfɔːr.tʃən.ət/

Unfortunate

不運な; 残念な
Meaning
having bad luck; regrettable or unlucky
Example
It was unfortunate that the meeting was cancelled at the last minute.
会議が最後の瞬間にキャンセルされたのは不運でした。
C1 adjective /ˈʌndərhænd/

underhand

不正
Meaning
done secretly and dishonestly; deceitful
Example
The politician was accused of using underhand tactics to win the election.
その政治家は選挙に勝つために不正な手段を使ったとして非難されました。
B1 verb /ˈʌpˌɡreɪd/

upgrade

アップグレード
Meaning
to raise something to a higher standard, improve
Example
We decided to upgrade the software to the latest version.
私たちはソフトウェアを最新バージョンにアップグレードすることに決めました。
A2 adjective /ʌnˈkʌmfətəbl/

Uncomfortable

不快
Meaning
causing or feeling physical or emotional discomfort
Example
He felt uncomfortable during the long meeting.
長い会議の間、彼は不快に感じました。
B2 noun /ʌnˈkaɪndnəs/

unkindness

不親切
Meaning
lack of kindness; cruel or inconsiderate behavior
Example
His unkindness hurt her feelings deeply.
彼の不親切は彼女の気持ちを深く傷つけた。
B2 adjective /ʌnˌkənˈdɪʃ.ən.əl/

Unconditional

無条件の
Meaning
not subject to any conditions; complete and absolute
Example
She offered her unconditional support to her friend in need.
彼女は困っている友人に無条件のサポートを提供しました。
B2 adjective /ˌʌnˈnoʊ.tɪst/

Unnoticed

気づかれなかった; 無視された
Meaning
not seen or observed; ignored
Example
His hard work went unnoticed by his manager.
彼の努力はマネージャーに気づかれませんでした。
B1 adjective /ʌnˈklɪər/

unclear

不明確
Meaning
not easy to understand; vague or ambiguous
Example
The instructions were unclear, so I asked for clarification.
指示が不明確だったので、私は説明を求めました。
C1 adjective /ˌʌnəbˈtruːsɪv/

unobtrusive

目立たない
Meaning
not attracting attention; blending in without causing notice
Example
The security cameras are designed to be unobtrusive.
セキュリティカメラは目立たないように設計されています。
B2 adjective /ˌʌnɪnˈtenʃənəl/

Unintentional

意図しない; 偶発的
Meaning
not done on purpose; accidental
Example
The damage to the car was unintentional.
車の損傷は意図しないものでした。
C2 verb /juˈzɜrp/

usurp

奪取
Meaning
to take someone's position of power illegally or by force
Example
The general tried to usurp the king's throne.
将軍は王の玉座を奪おうとした。
B2 adjective /ʌn.rɪˈleɪ.tɪd/

Unrelated

無関係な; 関連していない
Meaning
having no connection or relationship; not connected by family ties
Example
The two incidents were completely unrelated to each other.
二つの出来事は完全に無関係だった。
C2 adjective /ˌʌltrəˈmɒnteɪn/

ultramontane

教皇支持者
Meaning
beyond the mountains, especially referring to support for the Pope over local church authority
Example
The debate highlighted the ultramontane position in church politics.
その討論は教会政治におけるウルトラモンタンの立場を浮き彫りにした。
C2 noun /ˈʌn.dɚˌstɔː.ri/

understory

下層植物
Meaning
The layer of vegetation beneath the main canopy of a forest.
Example
The understory of a rainforest is home to small mammals and insects.
熱帯雨林の下層植物は小さな哺乳動物や昆虫の家です。
B1 adjective /ˌʌnɪkˈspektɪd/

Unexpected

予想外の; 驚くべき
Meaning
not expected or anticipated; surprising
Example
The unexpected news left everyone speechless.
予想外のニュースは、皆を言葉を失わせた。
C2 noun /ˈjuːnɪvəˌlɛns/

univalence

単価性
Meaning
The state of having a single valence or combining power, especially in chemistry.
Example
Hydrogen is characterized by its univalence in chemical reactions.
水素は化学反応においてその単価性によって特徴づけられています。
B2 adjective /ˈʌt.moʊst/

Utmost

最大の; 極限
Meaning
greatest; most extreme; maximum possible
Example
She showed utmost care while handling the fragile items.
彼女は壊れやすいアイテムを扱うとき、最大の配慮を示しました。
C2 verb /ˌʌn.dɪˈsiːv/

undeceive

誤解を解く
Meaning
To free someone from a misconception or false belief.
Example
She tried to undeceive him about the false rumors.
彼女は嘘の噂について彼を誤解を解こうとしました。
C1 adjective /ˌʌnsəˈfɪstɪˌkeɪtɪd/

unsophisticated

未洗練
Meaning
Lacking worldly experience, refinement, or complexity.
Example
The villagers led an unsophisticated but happy life.
村人たちは未洗練だが、幸せな生活を送っていた。
C1 adjective /ʌnˈsiːmli/

unseemly

不適切な
Meaning
Not proper or appropriate in behavior or appearance; unbecoming.
Example
His unseemly remarks embarrassed everyone at the dinner table.
彼の不適切な発言はディナーテーブルで皆を困らせました。
C1 adjective /ˌʌnəˈsjuːmɪŋ/

unassuming

控えめな
Meaning
Not pretentious or arrogant; modest.
Example
Despite his success, he remained unassuming and humble.
成功にもかかわらず、彼は控えめで謙虚なままでした。
C1 noun /ˈʌndərˌwɜːrld/

underworld

アンダーワールド
Meaning
The criminal world of organized crime or the mythical world of the dead.
Example
The detective spent years studying the secrets of the underworld.
探偵はアンダーワールドの秘密を何年も研究していました。
C1 adjective /ˈʌpərˌmoʊst/

uppermost

最上
Meaning
situated at the highest place or most important
Example
Her family's safety was uppermost in her mind during the crisis.
危機の間、彼女の心の中で最も重要なのは家族の安全でした。
A2 noun /ˈʌndərweər/

underwear

下着
Meaning
Clothing worn beneath outer clothes, typically next to the skin.
Example
He bought new underwear for the trip.
彼は旅行のために新しい下着を買った。
B2 adverb /ʌnˈkaɪndli/

unkindly

意地悪に
Meaning
in a cruel, harsh, or unsympathetic manner
Example
She spoke unkindly about her colleague during the meeting.
彼女は会議中に同僚のことを意地悪に話した。
C2 verb /ˌʌndərˈɡɜːrd/

undergird

支える、強化する
Meaning
to provide support or foundation for; to strengthen
Example
Strong values undergird a healthy society.
強い価値観は健康な社会を支えています。
C1 adjective /ʌnˈkʌltʃəd/

Uncultured

無教養な; 教養のない
Meaning
lacking good manners, refinement, or education; uncivilized
Example
His uncultured behavior embarrassed everyone at the dinner party.
彼の無教養な行動はディナーパーティーでみんなを困らせた。
C1 adjective + noun ʌnˈpresɪdentɪd ˈnɒlɪdʒ

unprecedented knowledge

前例のない知識
Meaning
Information or understanding that has never been obtained or achieved before.
Example
Artemis will provide unprecedented knowledge about the solar system.
アルテミスは太陽系に関する前例のない知識を提供する。