undermine
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B2 verb /ˌʌndərˈmaɪn/

undermine

削弱
Meaning
to gradually weaken or damage something or someone
Example
Constant criticism can undermine a child's confidence.
持续的批评可能会削弱孩子的自信心。
C1 adjective /ʌnˈsoʊld/

unsold

未售出的
Meaning
not sold; remaining without a buyer
Example
The unsold goods were returned to the warehouse.
未售出的商品被退回仓库。
B2 adjective /ʌnˈhɛlpfəl/

unhelpful

没有帮助的
Meaning
not providing help or support; making a situation harder rather than easier
Example
His unhelpful attitude slowed down the entire project.
他没有帮助的态度拖慢了整个项目。
B2 noun /ˈɜː.dʒən.si/

Urgency

紧急
Meaning
the quality of requiring immediate action or attention; pressing importance
Example
The urgency of the situation required immediate medical attention.
情况的紧急性要求立即的医疗关注。
B2 adjective /ʌnˈθɪŋkəbl/

Unthinkable

难以想象的
Meaning
impossible to conceive or imagine; beyond belief or consideration
Example
It was unthinkable that such a tragedy could happen in our peaceful town.
在我们和平的小镇上发生这样一场悲剧，简直是难以想象的。
C2 noun /ˈʌndərlɪŋ/

underling

下属
Meaning
a person of low rank or importance; a subordinate
Example
The manager ordered his underlings to finish the task quickly.
经理命令他的下属快速完成任务。
B2 adjective /ʌnˈfeɪθ.fəl/

Unfaithful

不忠诚
Meaning
not loyal or true to a spouse, partner, or commitment
Example
He was unfaithful to his wife for many years.
他对妻子不忠诚多年。
C1 adjective /ʌnˈtoʊld/

Untold

不可计数的; 无尽的
Meaning
very great in amount or degree; countless; immeasurable
Example
The earthquake caused untold damage to the city.
地震对城市造成了无法计数的损害。
B2 adjective /ʌnˈnætʃərəl/

Unnatural

不自然的
Meaning
not existing in nature; artificial; forced
Example
The actor's smile looked unnatural and forced.
演员的笑容看起来很不自然，很勉强。
B2 adverb /ʌnˈwɪlɪŋli/

unwillingly

不情愿地
Meaning
in a way that shows reluctance or lack of desire; not willingly
Example
She unwillingly agreed to attend the meeting.
她不情愿地同意参加会议。
C1 adjective /ʌnˈruːli/

Unruly

不守规矩的; 乱七八糟的;
Meaning
difficult to control or manage; disorderly and disruptive
Example
The unruly crowd refused to follow the safety instructions.
那群无法控制的人群拒绝遵循安全指令。
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.
这个工具的有用性在项目过程中变得显而易见。
C1 adjective /ˌjuːnɪˈsɛljʊlər/

unicellular

单细胞
Meaning
Consisting of a single cell.
Example
Amoebas are unicellular organisms.
变形虫是单细胞生物。
B1 adjective /juːˈnaɪtɪd/

United

联合的; 一致的; 团结的
Meaning
joined together for a common purpose; in agreement
Example
The team was united in their goal to win.
团队在他们的目标上达成了统一。
A2 adjective /ˈjuːs.ləs/

Useless

无用
Meaning
having no beneficial purpose; not useful
Example
This broken computer is completely useless.
这个坏掉的电脑完全是无用的。
A1 verb /ˌʌndərˈstænd/

understand

理解
Meaning
to know the meaning of something; to comprehend
Example
Do you understand the instructions?
你理解这些指示吗?
B1 adjective /ʌnˈwel/

Unwell

不舒服; 生病
Meaning
not in good health; feeling sick or ill
Example
She has been feeling unwell since yesterday.
她从昨天开始感到不舒服。
A1 adverb /ʌp/

up

向上
Meaning
towards a higher position or level
Example
He climbed up the ladder quickly.
他迅速爬上了梯子。
C2 verb /ʌnˈfɛtər/

unfetter

解开束缚
Meaning
to release from restraint or restriction; to free
Example
The new law will unfetter small businesses from excessive regulations.
新法律将使小企业免于过多的规定。
B2 adjective /ˈʌpˌhɪl/

Uphill

困难的; 需要巨大努力的; 向上的倾斜
Meaning
difficult; requiring great effort; sloping upward
Example
Learning a new language can be an uphill battle.
学习一门新语言可能是一个艰难的战斗。
B1 adjective /ʌnˈklɪər/

unclear

不清楚
Meaning
not easy to understand; vague or ambiguous
Example
The instructions were unclear, so I asked for clarification.
说明不清楚，所以我要求澄清。
C1 adjective ʌnˈpær.ə.leld

Unparalleled

无与伦比
Meaning
Having no equal; unmatched, peerless, and supreme in quality or achievement.
Example
The unparalleled beauty of the Taj Mahal amazes visitors.
泰姬陵无与伦比的美丽使游客惊叹。
B2 adjective /ʌnˈskɪld/

Unskilled

无技能的; 无技术的工人
Meaning
lacking technical training or ability; not requiring special skills
Example
Many unskilled workers are looking for training opportunities.
许多没有技能的工人正在寻找培训机会。
C1 noun /ʌnkənˈsɜːrn/

Unconcern

漠不关心
Meaning
lack of worry or interest; indifference
Example
She showed complete unconcern about the criticism.
她对批评表现出了完全的漠不关心。
B2 noun /ʌnˈkaɪndnəs/

unkindness

不友善
Meaning
lack of kindness; cruel or inconsiderate behavior
Example
His unkindness hurt her feelings deeply.
他的不友善深深伤害了她的感情。
C1 adjective /ˌʌnsəˈfɪstɪˌkeɪtɪd/

unsophisticated

不复杂
Meaning
Lacking worldly experience, refinement, or complexity.
Example
The villagers led an unsophisticated but happy life.
村民过着简单而幸福的生活。
C1 noun /ˈʌndərˌwɜːrld/

underworld

地下世界
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.
侦探花了很多年研究地下世界的秘密。
C2 adjective /ʌnˈflæpəbəl/

unflappable

冷静沉着
Meaning
calm and composed, especially in difficult situations
Example
Despite the crisis, he remained unflappable and confident.
尽管面临危机，他依然保持冷静沉着，充满自信。
B2 adjective /ʌnˈstɛdi/

unsteady

不稳定的
Meaning
not firm or stable; likely to change or fail
Example
She felt unsteady on her feet after the long journey.
长途旅行后，她感到站立不稳。
B2 verb /ˌʌndərˈɡoʊ/

undergo

经历
Meaning
to go through something, especially something unpleasant or difficult
Example
She had to undergo surgery to recover.
她不得不接受手术以恢复。
B1 noun /ˌʌnɪmˈplɔɪmənt/

Unemployment

失业
Meaning
the state of being unemployed; lack of paid work
Example
The unemployment rate has increased significantly this year.
今年失业率显著上升。
B2 noun /ʌnˈkɒnʃəsnəs/

unconsciousness

无意识
Meaning
the state of being unaware of and unable to respond to one's surroundings
Example
After the accident, he was in a state of unconsciousness for several hours.
事故后，他昏迷了几个小时。
B2 adjective /ʌnˈsuːtəbl/

Unsuitable

不适合; 不合适
Meaning
not fitting or appropriate for a particular purpose or situation
Example
This formal dress is unsuitable for a casual beach party.
这件正式的衣服不适合参加随意的海滩派对。
C1 adjective ʌnˈskruːpjʊləs

unscrupulous

不道德的
Meaning
Having or showing no moral principles; not honest or fair.
Example
Unscrupulous peers can lead adolescents to delinquency.
不道德的同龄人可能会导致青少年犯罪。
A2 noun /ˈjuːzər/

user

用户
Meaning
a person who uses or operates something
Example
He is a frequent user of this app.
他是这个应用程序的常用用户。
C1 verb /ˌʌndərˈlaɪ/

underlie

位于...之下
Meaning
to be the hidden cause or basis of something
Example
Strong cultural traditions underlie the community's practices.
强大的文化传统是社区实践的基础。
C1 noun /ˈʌp.tɜːn/

upturn

改善
Meaning
An improvement or upward trend in a situation, especially in business or economy.
Example
The company experienced an upturn in sales last quarter.
该公司在上个季度销售情况有所改善。
C1 adjective /ʌnˈtaɪərɪŋ/

Untiring

不知疲倦的; 坚持不懈的; 永不止步的
Meaning
continuing without stopping; persistent; tireless
Example
Her untiring efforts finally led to success.
她的不知疲倦的努力最终带来了成功。
B2 verb /ˌʌndərˈɛstɪmeɪt/

underestimate

低估
Meaning
To judge something as less important or smaller than it really is.
Example
Never underestimate the power of teamwork.
永远不要低估团队合作的力量。
B1 adjective ʌnˈplænd

unplanned

未计划的
Meaning
Not planned or arranged in advance; happening spontaneously without preparation.
Example
Unplanned urbanization contributes to environmental issues.
无计划的城市化会加剧环境问题。
B1 noun /ˈjuːnjən/

Union

联合
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.
两家公司的联合创造了一个强大的公司。
B2 adjective /ˈʌl.tɪ.mət/

Ultimate

最终的; 极致的; 终极的
Meaning
being the best or most extreme example of its kind; final; last
Example
This is the ultimate test of your skills.
这是你技能的终极考验。
B2 adjective /ʌnˈhɜːd/

Unheard

未听到的; 未知的
Meaning
not heard or listened to; not given a hearing; unknown or unfamiliar
Example
His complaints went unheard by the management.
他的投诉没有被管理层听到。
B2 adjective /ʌnfəˈmɪl.jər/

Unfamiliar

不熟悉的; 陌生的
Meaning
not known or recognized; strange
Example
The city was unfamiliar to me since I had never been there before.
这座城市对我来说很陌生，因为我以前从未去过那里。
A2 noun /ʌmˈbrɛlə/

umbrella

伞
Meaning
A device used for protection against rain or sun, typically consisting of a collapsible canopy mounted on a central rod.
Example
She opened her umbrella as it started to rain.
下雨时她打开了她的伞。
B2 adverb juːˈnæn.ɪ.məs.li

unanimously

一致通过
Meaning
With the agreement of all people involved; without opposition.
Example
The proposal was unanimously accepted.
提案得到了全体一致通过。
C2 noun /ˈjuːzjuːfrʌkt/

usufruct

使用权
Meaning
The legal right to use and enjoy the benefits of someone else’s property without owning it.
Example
The tenant had the usufruct of the land but not its ownership.
租户有权使用这片土地，但没有所有权。
C2 adjective /ˌʌnɪkˈsɛpʃənəbl/

unexceptionable

无可指摘
Meaning
Not open to objection; acceptable and unobjectionable
Example
His behavior was unexceptionable throughout the event.
他的行为在整个事件中都是无可指摘的。
C1 adjective /ʌnˈtaɪmli/

Untimely

不合时宜
Meaning
happening at an inappropriate or inconvenient time; premature
Example
His untimely death at the age of thirty shocked everyone.
他的过早死亡在30岁时震惊了所有人。
A1 noun /ˈʌŋkəl/

uncle

叔叔/舅舅
Meaning
the brother of one's father or mother
Example
My uncle is visiting us next week.
我的叔叔下周会来看我们。
C2 noun /ˈjuːnɪvəˌlɛns/

univalence

单价性
Meaning
The state of having a single valence or combining power, especially in chemistry.
Example
Hydrogen is characterized by its univalence in chemical reactions.
氢气在化学反应中以其单价性为特点。
A2 conjunction /ʌnˈlɛs/

unless

除非
Meaning
except if
Example
We won't go unless it stops raining.
除非雨停了，否则我们不去。
C2 noun /ˈʌp.wel.ɪŋ/

upwelling

上升流
Meaning
An oceanographic phenomenon that involves wind-driven motion of dense, cooler, and nutrient-rich water towards the ocean surface.
Example
Upwelling brings nutrients to the ocean surface.
上升流将营养物质带到海洋表面。
B2 noun /ˈʌndərkləʊðz/

underclothes

内衣
Meaning
Clothing worn beneath outer clothes, such as underwear or lingerie
Example
He folded his underclothes neatly before packing them.
他在打包前把内衣叠得整整齐齐。
C2 adjective /ʌnˈwiːldi/

unwieldy

笨重
Meaning
Difficult to carry or move because of its size, shape, or weight.
Example
The box was too unwieldy to carry up the stairs.
这个盒子太笨重了，无法把它提上楼梯。
B1 adjective /ˌʌnˈɪntrəstɪŋ/

uninteresting

无趣的
Meaning
not holding attention or curiosity; boring
Example
The lecture was uninteresting and difficult to stay focused on.
这次讲座很无趣，很难集中注意力。
C1 adjective /ʌnˈkʌltʃəd/

Uncultured

不文明的; 无文化的
Meaning
lacking good manners, refinement, or education; uncivilized
Example
His uncultured behavior embarrassed everyone at the dinner party.
他在晚宴上的不文明行为让所有人感到尴尬。
C1 adjective /ˌʌnɪmˈplɔɪəbəl/

unemployable

不适合就业
Meaning
Not able to be employed; lacking the skills or qualities necessary for employment
Example
Due to his criminal record, he was considered unemployable in most companies.
由于他的犯罪记录，他在大多数公司被认为是不适合就业。
C2 adjective /ʌnˈtiːtʃəbəl/

unteachable

不可教的
Meaning
not able or willing to learn; resistant to instruction or guidance
Example
He was so stubborn that he became almost unteachable.
他非常固执，几乎变得不可教。
B2 adjective /ˌʌndɪˈzaɪərəbl/

Undesirable

不受欢迎的; 有害的; 令人不快的
Meaning
not wanted or wished for; harmful or unpleasant
Example
The new policy had several undesirable consequences.
新政策带来了几个不受欢迎的后果。
C1 adjective /ʌnˈweɪ.vər.ɪŋ/

unwavering

坚定
Meaning
Steady or resolute; not wavering.
Example
He showed unwavering dedication to his goal.
他展示了对目标的坚定承诺。
B1 adjective /ˌʌnˈpeɪd/

Unpaid

未支付的; 无薪的
Meaning
not paid for; without payment or salary
Example
She worked as an unpaid intern for six months.
她作为一名无薪实习生工作了六个月。
C1 adverb /ʌnˈnætʃrəli/

unnaturally

不自然地
Meaning
in a way that is not natural or normal; excessively or strangely
Example
He smiled unnaturally, making everyone feel uncomfortable.
他不自然地笑了，让每个人都感到不舒服。
C1 adjective /ʌnˈmaɪndfəl/

Unmindful

不留心的; 疏忽的;
Meaning
not paying attention; careless; heedless
Example
She was unmindful of the danger around her.
她没有注意到周围的危险。
B2 verb /ʌnˈkʌvə(r)/

uncover

揭示
Meaning
to reveal something that was hidden or secret
Example
The investigation uncovered new evidence.
调查揭示了新的证据。
A2 adjective /ʌnˈhel.θi/

Unhealthy

不健康的; 有害的
Meaning
harmful to health; not in good health; detrimental to well-being
Example
Eating too much fast food is unhealthy for your body.
吃太多快餐对你的身体不健康。
B2 adverb /ʌnˈplɛzəntli/

unpleasantly

令人不快地
Meaning
in a way that causes discomfort, annoyance, or displeasure; in an unfriendly or disagreeable manner
Example
The room was unpleasantly hot during the afternoon.
下午房间里热得令人不快。
B2 adverb /ˈʌt.ə.li/

Utterly

完全地; 绝对地; 完整地
Meaning
completely; absolutely; totally
Example
The movie was utterly boring and I fell asleep.
电影完全无聊，我睡着了。
C1 noun /ˌʌnbɪˈliːf/

Unbelief

不信
Meaning
lack of religious belief; skepticism or doubt
Example
His unbelief in the supernatural made him a skeptic.
他对超自然的怀疑使他成为了一个怀疑者。
C1 adjective /ʌnˈsaɪtli/

unsightly

难看
Meaning
Unpleasant to look at; ugly.
Example
The garbage pile created an unsightly view in the park.
垃圾堆在公园里创造了一个难看的景象。
C1 adjective /ʌnˈbraɪdld/

unbridled

无法控制的
Meaning
Uncontrolled and unrestrained.
Example
The protesters showed unbridled enthusiasm for change.
抗议者展示了对改变的无法抑制的热情。
C1 adjective /ʌnˈkwaɪ.ət/

Unquiet

不安的; 焦虑的; 激动的
Meaning
restless; unable to remain still or quiet; anxious or troubled
Example
She spent an unquiet night worrying about the exam results.
她度过了一个不安的夜晚，担心考试结果。
C2 verb /ˌʌn.dɪˈsiːv/

undeceive

解惑
Meaning
To free someone from a misconception or false belief.
Example
She tried to undeceive him about the false rumors.
她试图让他摆脱这些错误的谣言。
B2 adjective /juːˈnæn.ɪ.məs/

Unanimous

一致的
Meaning
fully in agreement; shared by all
Example
The committee reached a unanimous decision.
委员会达成了一致的决定。
C2 noun /ʌnˈkloʊðɪŋ/

unclothing

脱衣
Meaning
the act or process of removing clothing
Example
The child quickly ran inside for unclothing after playing in the mud.
孩子在泥地玩耍后迅速跑进去脱衣。
C1 verb /ʌnˈɜːθ/

unearth

发掘
Meaning
To dig up from the ground or to discover something hidden.
Example
Archaeologists unearthed ancient artifacts at the site.
考古学家在遗址发掘了古代文物。
C1 adverb /ˌʌnkənˈvɛnʃənəli/

unconventionally

非传统地
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.
她穿着非传统地，混搭大胆的颜色和图案，让每个人都感到惊讶。
A1 preposition /ˈʌndər/

under

下
Meaning
in or to a lower position than something
Example
The cat is under the table.
猫在桌子下面。
C2 adverb /ʌnˈɜːrɪŋli/

unerringly

毫无错误
Meaning
Without making any mistakes; always accurate
Example
The archer aimed unerringly at the target.
弓箭手毫无错误地瞄准了目标。
C2 verb /ʌpˈbreɪd/

upbraid

斥责
Meaning
To scold or criticize someone harshly.
Example
The teacher upbraided the student for being late again.
老师因为学生再次迟到而训斥了他。
C1 noun /ˈʌndərdɒɡ/

underdog

逆袭者
Meaning
a competitor thought to have little chance of winning; a weaker party in a contest
Example
The underdog team surprised everyone by winning the championship.
逆袭者队伍通过赢得锦标赛让所有人都惊讶。
C2 adjective /ʌnˈfeɪnd/

unfeigned

真诚
Meaning
genuine; not pretended or insincere
Example
She expressed unfeigned joy at her friend's success.
她在朋友的成功上表达了真诚的喜悦。
B1 verb /ʌnˈpæk/

unpack

拆开
Meaning
to remove items from a container; to explain or analyze something in detail
Example
After arriving home, she began to unpack her suitcase.
到家后，她开始拆开自己的行李箱。
B1 adverb /ˌʌpsaɪd ˈdaʊn/

Upside-down

倒过来
Meaning
with the upper part at the bottom; in or into a reversed position
Example
The picture was hanging upside-down on the wall.
图片倒挂在墙上。
B1 adjective /ʌnˈfeər/

Unfair

不公平; 不正当;
Meaning
not right or just; treating people in a way that favors some over others
Example
It's unfair to blame her for something she didn't do.
指责她做了她没有做的事是不公平的。
C1 verb /ʌnˈnɜːrv/

unnerve

失去信心
Meaning
to make someone lose confidence, courage, or composure
Example
The hostile questions began to unnerve the witness.
敌对问题开始让证人感到不安。
C1 adjective /ʌnˈsteɪtɪd/

unstated

未声明
Meaning
not expressed directly in words; implied or left unsaid
Example
The contract included several unstated expectations.
合同包括了几个未声明的期望。
B2 adverb /ˈɜːrdʒəntli/

urgently

紧急地
Meaning
in a way that requires immediate attention or action
Example
The patient urgently needs medical attention.
病人紧急地需要医疗救助。
C2 adjective /ʌnˈspɛərɪŋ/

unsparing

无情的
Meaning
Showing no mercy or generosity; harsh or severe.
Example
The critic was unsparing in his review of the play.
评论家在他的剧评中毫不留情。
C2 noun /ˈɜːrtʃɪn/

urchin

街头小孩
Meaning
a mischievous or poorly dressed child, often from the streets
Example
The ragged urchins played by the riverbank.
那些穿着破烂的街头小孩在河边玩耍。
B2 adjective /ʌnˈendɪŋ/

Unending

无尽的
Meaning
continuing forever; without end
Example
The unending rain made the day feel gloomy.
无尽的雨让这一天显得阴沉。
C2 adjective /ˌʌltrəˈmʌndeɪn/

ultramundane

超凡
Meaning
Relating to things beyond the physical world; supernatural or transcendental.
Example
Philosophers often discuss ultramundane realities beyond human perception.
哲学家们常常讨论超越人类感知的超凡现实。
A2 adjective /ˈjuːʒəl/

usual

常见
Meaning
habitually or typically occurring or done
Example
It’s our usual meeting spot.
这是我们常见的会议地点。
B2 adjective /ˌʌnˈnoʊ.tɪst/

Unnoticed

未被注意到; 被忽视
Meaning
not seen or observed; ignored
Example
His hard work went unnoticed by his manager.
他的辛勤工作没有被经理注意到。
C2 noun /ˈʌŋkʃən/

unction

涂抹
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.
牧师庄重地进行了神圣的涂抹仪式。
B2 adjective /ʌnˈraɪp/

Unripe

未成熟的
Meaning
not fully developed or matured; not ready to be eaten
Example
The unripe bananas will turn yellow in a few days.
未成熟的香蕉几天后会变黄。
C2 noun /juːˈkeɪs/

ukase

法令
Meaning
An authoritative decree or order, especially one issued by a sovereign or government.
Example
The czar issued a ukase restricting the freedom of the press.
沙皇发布了一项限制新闻自由的法令。
B2 adjective /ˌjuːnɪˈvɜːrsəl/

Universal

普遍的
Meaning
applicable to all cases; existing everywhere
Example
Music is a universal language that everyone understands.
音乐是一种普遍的语言，人人都能理解。
B2 adverb /ʌnˈkɒnʃəsli/

unconsciously

无意识地
Meaning
without being aware of one's actions or surroundings
Example
She unconsciously tapped her foot to the rhythm of the music.
她无意识地跟着音乐的节奏轻轻跺脚。
C1 adjective + noun ʌnˈpresɪdentɪd ˈnɒlɪdʒ

unprecedented knowledge

前所未有的知识
Meaning
Information or understanding that has never been obtained or achieved before.
Example
Artemis will provide unprecedented knowledge about the solar system.
阿尔忏将提供关于太阳系的前所未有的知识。
B2 adjective /ʌnˈdʒʌst/

Unjust

不公正的; 错误的
Meaning
not fair or right; morally wrong
Example
The punishment was unjust for such a minor offense.
这个惩罚对于如此轻微的罪行来说是不公正的。
B2 adjective /ʌnˈiːzi/

Uneasy

不安的; 焦虑的; 不舒服的
Meaning
worried; anxious; uncomfortable; restless
Example
She felt uneasy about walking alone at night.
她在夜晚独自行走时感到不安。
B1 adjective /ˈɜːrdʒənt/

Urgent

紧急
Meaning
requiring immediate action or attention; pressing
Example
The patient needs urgent medical attention.
病人需要紧急医疗照顾。
B2 adjective /ʌnˈfeɪv(ə)rəbəl/

unfavorable

不利
Meaning
not beneficial or advantageous; showing disapproval or opposition
Example
The proposal received an unfavorable response from the committee.
提案收到了委员会的负面回应。
C2 noun /ˈʌm.brə/

Umbra

完全的阴影，太阳黑子的黑暗中心
Meaning
the fully shaded inner region of a shadow cast by an opaque object; the dark center of a sunspot
Example
During the eclipse, we stood in the moon's umbra.
在日食期间，我们站在月亮的本影中。
C1 adjective /ʌnˈwɪtɪŋ/

unwitting

无意的
Meaning
Not aware of what is happening; done without realizing.
Example
She became an unwitting participant in the scam.
她成了这场骗局中的一个无意的参与者。
C2 verb /ʌpˈhiːv/

upheave

抬起
Meaning
to lift or raise something forcefully; to cause to rise suddenly
Example
The workers had to upheave the heavy stone to clear the path.
工人们不得不抬起重石来清理道路。
B2 verb /ʌnˈveɪl/

unveil

揭示
Meaning
to reveal or disclose something, especially in a formal manner
Example
The company will unveil a new product next week.
公司将在下周揭示一款新产品。
B1 adjective /ʌnˈwɒn.tɪd/

Unwanted

不受欢迎的
Meaning
not desired or welcome; not wanted
Example
He felt like an unwanted guest at the meeting.
他在会议上觉得自己像个不受欢迎的客人。
B1 adjective /ʌnˈsɜːrtən/

Uncertain

不确定
Meaning
not able to be relied on; not known or definite; not having reliable knowledge
Example
I am uncertain about my future career plans.
我对未来的职业规划感到不确定。
B2 adjective /ˌʌndɪˈveləpt/

Undeveloped

未开发的; 未成熟的; 原始的
Meaning
not yet developed; immature or primitive
Example
The undeveloped land was later turned into a park.
未开发的土地后来被改建成了一个公园。
C1 adjective /ʌnˈkwes.tʃən.ə.bl̩/

Unquestionable

无可争议的; 确定的
Meaning
not able to be disputed or doubted; certain and beyond doubt
Example
Her honesty and integrity are unquestionable qualities.
她的诚实和正直是无可争议的品质。
B2 adjective /ˌʌn.kəʊˈɒp.ər.ə.tɪv/

uncooperative

不合作的
Meaning
not willing to help or work with others; unhelpful
Example
The witness was uncooperative and refused to answer questions.
证人不合作，拒绝回答问题。
C1 adjective /ʌnˈseɪvəri/

unsavory

令人不快
Meaning
Disagreeable, unpleasant, or morally offensive.
Example
The politician was linked to an unsavory scandal.
那位政治家与一宗令人不快的丑闻有关。
C2 adjective /ʌnˈwəʊntɪd/

unwonted

不寻常
Meaning
Unusual, uncommon, or out of the ordinary.
Example
She spoke with an unwonted gentleness that surprised everyone.
她以一种不寻常的温柔说话，令所有人都感到惊讶。
C1 noun /ˈʌp.raɪt.nəs/

Uprightness

正直; 正义
Meaning
the quality of being honest and morally correct; integrity
Example
His uprightness in business dealings earned him great respect.
他在商业中的正直赢得了很大的尊重。
C2 adjective /ʌnˈɡeɪnli/

ungainly

笨拙
Meaning
Awkward, clumsy, or lacking grace in movement or appearance.
Example
The tall boy moved in an ungainly manner.
那个高个男孩以笨拙的方式走动。
C1 noun /ʌnˈfeɪθfʊlnəs/

unfaithfulness

不忠
Meaning
the quality of being disloyal or not faithful; breach of trust or fidelity
Example
His unfaithfulness led to the end of their marriage.
他的不忠导致了他们婚姻的结束。
A2 adjective /ʌnˈkʌmf.tə.bəl/

Uncomfortable

不舒服
Meaning
causing or feeling slight pain or physical discomfort; making someone feel embarrassed, awkward, or anxious
Example
The chair was so uncomfortable that I couldn't sit in it for more than ten minutes.
这个椅子太不舒服了，我坐在上面超过十分钟就坐不下来了。
C2 verb /ˈʌndərˌmæn/

underman

人员不足
Meaning
to supply with fewer workers or personnel than needed
Example
The hospital was undermanned during the flu outbreak.
医院在流感爆发期间人手不足。
B1 adjective /ʌnˈjuː.ʒu.əl/

Unusual

不寻常; 奇怪;
Meaning
not typical; strange; different from what is normal
Example
She wore an unusual dress to the party.
她穿了一件不寻常的衣服去参加派对。