Utility
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B2 noun /juːˈtɪl.ə.ti/

Utility

效用; 益处; 公共服务
Meaning
the state of being useful, profitable, or beneficial; a public service
Example
The utility of solar panels increases with rising electricity costs.
随着电费上涨，太阳能板的效用也在增加。
C1 adjective ʌnˈtʃɑːtɪd

uncharted

未标记
Meaning
Not mapped or surveyed; unknown or unexplored.
Example
The mission aimed to explore uncharted areas of the planet.
该任务旨在探索星球上未标记的区域。
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。
C2 adjective /ˌʌnəˈsweɪdʒd/

unassuaged

未缓解
Meaning
Not made less intense or relieved; unrelieved.
Example
His grief remained unassuaged despite the passage of time.
他的痛苦尽管时间流逝依然未缓解。
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 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。
B1 adjective /ˌʌnsəkˈsesfl/

Unsuccessful

失败的; 没有成功的;
Meaning
not achieving desired aims or results; failing to accomplish a purpose
Example
His unsuccessful attempt to climb the mountain left him disappointed.
他未能成功登上山顶，感到失望。
B1 adjective /ʌnˈpɒpjʊlə/

unpopular

不受欢迎的
Meaning
not liked or supported by many people
Example
The decision was unpopular with the public.
这个决定在公众中不受欢迎。
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。
C1 adjective /ˌʌnprɪˈtɛnʃəs/

unpretentious

谦虚的
Meaning
modest; not attempting to impress others with appearance or importance
Example
She lives in an unpretentious home but is very happy.
她住在一个谦虚的家里，但非常快乐。
C1 adjective /ʌnˈɒnəd/

unhonoured

未受尊敬的
Meaning
not respected or given the recognition that is deserved; treated without honor
Example
He felt unhonoured after his years of service were ignored.
他的多年服务被忽视后，他感到自己未受尊敬。
A2 adjective /ˈʌɡ.li/

Ugly

丑陋的; 可憎的; 可怕的
Meaning
unpleasant or repulsive in appearance; morally reprehensible
Example
The old building looked ugly after years of neglect.
这座老建筑在多年疏忽之后看起来很丑。
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。
C1 adjective /ʌnˈkɒm.prə.maɪ.zɪŋ/

Uncompromising

不妥协, 固执
Meaning
unwilling to change one's views or to agree about something; showing an unwillingness to make concessions to others
Example
He was uncompromising in his demand for a full apology.
他在要求完全道歉时非常坚决。
B2 adjective /ʌnˈkwɒl.ɪ.faɪd/

Unqualified

不合格的; 无资格的;
Meaning
not having the necessary skills or qualifications; complete or absolute
Example
He was unqualified for the engineering position due to lack of experience.
他因缺乏经验而不适合这个工程职位。
C1 adjective /ʌnˈsəʊʃəbl/

unsociable

不合群的
Meaning
not enjoying the company of others; avoiding social interaction
Example
He became unsociable after moving to a new city.
搬到新城市后，他变得不合群。
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?
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。
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。
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 adjective /ʌnˈsʌlid/

unsullied

无暇
Meaning
not spoiled or made impure; perfectly clean or pure
Example
His reputation remained unsullied despite the accusations.
尽管有指控，他的声誉仍然无暇。
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 adjective /ʌnˈsiːn/

Unseen

看不见的；未曾看到或注意到的
Meaning
not previously seen or noticed; invisible; hidden
Example
The unseen forces of nature can be very powerful.
自然界的看不见的力量可能非常强大。
C2 adjective /ˌʌnɪmˈpiːtʃəbl/

unimpeachable

无可指摘
Meaning
Not able to be doubted, questioned, or criticized; completely trustworthy.
Example
She is known for her unimpeachable honesty.
她因其无可指摘的诚实而闻名。
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。
B2 adjective /ʌnˈlɪmɪtɪd/

unlimited

无限
Meaning
without any limits or restrictions
Example
The internet plan offers unlimited data for the whole month.
该互联网计划提供整个一个月的无限数据。
B2 adjective /ʌnˈwɜːrði/

Unworthy

不配; 没有价值
Meaning
not deserving respect or attention; lacking worth or merit
Example
He felt unworthy of such praise and recognition.
他觉得自己不配得到这样的赞扬和认可。
C1 noun ˈʌp.raɪ.zɪŋ

uprising

起义
Meaning
An act of resistance or rebellion; a revolt against an authority or government.
Example
The uprising marked the beginning of the revolution.
起义标志着革命的开始。
B2 adjective /ʌnˈdɪvaɪdɪd/

Undivided

完整的; 完全的; 不分开或不分裂
Meaning
whole; complete; not separated or split
Example
The team showed undivided attention to the coach's instructions.
团队对教练的指示表现出了完整的注意力。
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.
她对这个问题的理解令人印象深刻。
C2 adjective /ˌʌnsɛrəˈmoʊniəs/

unceremonious

不拘礼节/粗鲁
Meaning
Done without formality or courtesy; abrupt or rude.
Example
He made an unceremonious exit from the party.
他从派对上不拘礼节地离开。
C1 noun /ˈʌlsər/

ulcer

Meaning
a sore on the skin or a mucous membrane that does not heal easily
Example
The doctor prescribed medicine to treat the stomach ulcer.
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。
C2 adjective /ʌnˈmɪtɪɡeɪtɪd/

unmitigated

完全
Meaning
absolute; not lessened or moderated
Example
The meeting was an unmitigated disaster.
会议是一次完全的灾难。
C1 adjective /ʌnˈduː/

Undue

过度的; 不适当的; 超过必要或适当的
Meaning
excessive; inappropriate; more than is necessary or proper
Example
The teacher complained about undue pressure from parents.
老师抱怨家长施加的过度压力。
C1 adjective /ʌnˈmænɪdʒəbəl/

Unmanageable

无法控制的; 失控
Meaning
difficult or impossible to control or handle
Example
The large class became unmanageable without proper supervision.
没有适当的监督，班级变得无法控制。
C2 adjective /ˈɜːrsaɪn/

ursine

熊似的
Meaning
Relating to or resembling a bear.
Example
The man’s ursine strength amazed everyone.
那个人熊似的力量让所有人都吃惊。
C1 adjective /ˌʌnbɪˈliːvɪŋ/

unbelieving

不相信的
Meaning
Not willing or able to believe; skeptical or doubtful
Example
She gave him an unbelieving look when he claimed to have met a celebrity.
当他声称见过一位名人时，她给了他一个不相信的眼神。
B2 noun /ˌʌnəˌveɪləˈbɪləti/

unavailability

不可用性
Meaning
The state of being not available or not accessible.
Example
The unavailability of the manager caused a delay in the project.
经理的不可用性导致了项目的延误。
C2 adjective /ʌnˈstɪntɪŋ/

unstinting

慷慨的
Meaning
given generously without holding back
Example
She received unstinting support from her family.
她从家人那里得到了慷慨的支持。
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。
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。
B2 noun ˈjuːnəti

unity

团结
Meaning
The state of being united or joined as a whole.
Example
Unity among people led to victory.
人们之间的团结带来了胜利。
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。
C2 noun/verb /ˈʌpˌkæst/

upcast

向上投掷
Meaning
Verb: To cast or throw upward. Noun: Something thrown or directed upward.
Example
The fisherman upcast his net into the air.
渔夫把他的网投向空中。
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。
C1 adjective /ˌʌndərˈsteɪtɪd/

understated

低调的
Meaning
Presented in a subtle and restrained way.
Example
She wore an elegant but understated dress.
她穿了一件优雅但低调的裙子。
A2 noun /ˈʌndərweər/

underwear

内衣
Meaning
Clothing worn beneath outer clothes, typically next to the skin.
Example
He bought new underwear for the trip.
他为旅行买了新的内衣。
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。
C2 verb /ˌʌndərˈɡɜːrd/

undergird

支持，强化
Meaning
to provide support or foundation for; to strengthen
Example
Strong values undergird a healthy society.
强大的价值观支撑着一个健康的社会。
C1 adjective /ˌʌn.əˈdʌl.tə.reɪ.tɪd/

Unadulterated

纯净的
Meaning
not mixed or diluted with any different or extra elements; pure
Example
She felt unadulterated joy when she heard the news.
当她听到这个消息时，她感到纯净的快乐。
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。
C1 verb /ˌʌn.dəˈtʃɑːrdʒ/

undercharge

收取较少费用
Meaning
To charge less than the correct or fair amount.
Example
The shopkeeper accidentally undercharged me for the groceries.
店主不小心少收了我购买食品的钱。
C1 verb /ʌnˈkɔrk/

uncork

开瓶
Meaning
To remove the cork from a bottle; to open a bottle, especially of wine
Example
He uncorked the wine and poured a glass for everyone.
他开了葡萄酒，并为每个人倒了一杯。
C2 noun /ˈʌn.dɚˌstɔː.ri/

understory

下层植被
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.
雨林的下层植被是小型哺乳动物和昆虫的家园。
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 adjective /ˈʌpər/

upper

上层
Meaning
higher in position or rank
Example
The upper floor of the building is under renovation.
建筑物的上层正在翻修。
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 adjective /ʌnˈɪndʒərd/

uninjured

未受伤
Meaning
Without injury; not physically harmed.
Example
All the passengers were rescued uninjured.
所有乘客都没有受伤并被救援。
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。
C1 adjective /ˈʌpərˌmoʊst/

uppermost

最高
Meaning
situated at the highest place or most important
Example
Her family's safety was uppermost in her mind during the crisis.
她在危机期间心里最重要的是家庭的安全。
B2 adjective /ʌnˈbiːtən/

Unbeaten

不败的; 未被击败的
Meaning
not defeated; having never lost; undefeated
Example
The team remains unbeaten this season.
这个团队本赛季保持不败。
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 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。
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。
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。
B1 noun /ˈjuːnɪvɜːrs/

Universe

宇宙
Meaning
all existing matter and space; the cosmos
Example
Scientists study the universe to understand its mysteries.
科学家研究宇宙，以理解它的奥秘。
C1 noun /ˈʌndərˌteɪkər/

undertaker

殡葬员
Meaning
A person whose job is to prepare the dead for burial and arrange funerals.
Example
The undertaker prepared the body for the funeral service.
殡葬员为葬礼服务准备了尸体。
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。
B2 adjective /ʌnˈprɒf.ɪ.tə.bl̩/

Unprofitable

无利可图
Meaning
not yielding profit or gain; not producing financial benefit
Example
The unprofitable business was forced to close down after three years.
这个无利可图的生意在三年后被迫关闭。
C2 adjective /ʌnˈlɛtəd/

unlettered

文盲
Meaning
lacking education or the ability to read and write; illiterate
Example
The unlettered villagers relied on oral traditions to preserve their history.
那些文盲村民依赖口头传统来保存他们的历史。
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。
C1 noun /ˌʌl.tɪˈmeɪ.təm/

Ultimatum

最后通牒
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.
老板给了他一个最后通牒：要么改进，要么被解雇。
B2 verb /ˈjuːtɪlaɪz/

utilize

利用
Meaning
to make practical or effective use of something
Example
The company aims to utilize solar energy for production.
公司旨在利用太阳能进行生产。
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。
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。
C1 verb /ʌnˈsɛtl/

unsettle

扰乱
Meaning
To disturb or make someone feel anxious or uneasy.
Example
The sudden news unsettled the entire community.
突如其来的消息让整个社区感到不安。
C2 adjective /ˈʌŋk.tʃu.əs/

unctuous

阿谀奉承
Meaning
Excessively flattering or ingratiating; oily in texture.
Example
His unctuous tone made everyone uncomfortable.
他那种阿谀奉承的语气让每个人都感到不舒服。
C1 adjective /ˌʌndərˈsaɪzd/

undersized

尺寸过小
Meaning
Smaller than the usual or expected size.
Example
The undersized puppy struggled to keep up with its siblings.
这只尺寸过小的小狗很难跟上它的兄弟姐妹。
B2 adjective /ʌnˈriːzənəbəl/

unreasonable

不合理的
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.
经理提出了一个不合理的要求。
B2 adjective /ʌnˈfɪt/

Unfit

不适合; 不适当;
Meaning
not in good physical condition; unsuitable or inappropriate
Example
He was declared unfit for military service due to his poor health.
由于健康状况差，他被宣判不适合军事服务。
B2 noun ˌɜːbənaɪˈzeɪʃən

urbanization

城市化
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.
城市化导致更先进的基础设施。
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。
B2 noun /ˈjuː.sɪdʒ/

Usage

使用
Meaning
the action of using something; the way in which words are used in a language
Example
The dictionary explains the correct usage of difficult words.
词典解释了难词的正确用法。
C2 noun /ˌjuːzɜːrˈpeɪʃən/

usurpation

篡夺
Meaning
The act of taking someone's power or property illegally or by force.
Example
The general's usurpation of the presidency led to political unrest.
将军对总统职位的篡夺导致了政治动荡。
B2 adjective /ʌnəˈfreɪd/

unafraid

无畏
Meaning
Not feeling fear; brave or courageous
Example
She walked into the dark room, unafraid of what might be inside.
她走进黑暗的房间，无畏里面可能有什么。
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。
B2 adjective /ʌnprəˈdʌk.tɪv/

Unproductive

无效的; 不起作用的
Meaning
not achieving much; not producing good results
Example
The meeting was unproductive and wasted everyone's time.
会议是无效的，浪费了大家的时间。
B2 adjective /ʌnˈwaɪz/

unwise

不明智
Meaning
Showing poor judgment; not sensible or prudent.
Example
It would be unwise to invest all your money in one company.
把所有的钱都投入一家公司的做法不明智。
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。
C1 noun ˌʌndərˈprɪvəlɪdʒd ɡruːps

underprivileged groups

贫困群体
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.
贫困群体从社会倡议中受益。
C1 noun /ˈjuːnɪsən/

unison

齐声
Meaning
Simultaneous performance or utterance of action or speech.
Example
The choir sang in unison.
合唱团齐声唱歌。
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。
B1 adjective /ˈʌpˌkʌmɪŋ/

upcoming

即将到来
Meaning
about to happen or appear
Example
The upcoming event will be held next week.
即将到来的活动将在下周举行。
C2 noun /ˈʌŋɡwənt/

unguent

药膏
Meaning
A soothing or healing ointment applied to the skin.
Example
The doctor applied an unguent to heal the burn.
医生涂抹了药膏来治愈烧伤。
C1 verb /ʌpˈruːt/

uproot

拔除
Meaning
To pull something out of the ground; to remove or displace completely.
Example
They uprooted the old tree from the garden.
他们从花园里把老树拔了出来。
B2 adjective /ˌʌnprɪˈdɪktəbəl/

unpredictable

不可预测的
Meaning
not able to be predicted; changing suddenly and unexpectedly
Example
The weather in this region is highly unpredictable.
这个地区的天气非常不可预测。
C2 adjective /ˌʌn.rɪˈdʒɛn.ər.ət/

unregenerate

顽固
Meaning
Not reformed or showing no signs of change; stubbornly refusing to reform or repent.
Example
He remained an unregenerate opponent of progress.
他仍然是进步的顽固反对者。
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。
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。
B1 adjective /ˈɜːrbən/

urban

城市的
Meaning
related to, characteristic of, or situated in a city or town
Example
Urban areas often have higher population density than rural areas.
城市地区通常比乡村地区有更高的人口密度。
C1 adjective /ˌʌndərɪkˈspoʊzd/

underexposed

曝光不足，忽视的
Meaning
insufficiently exposed to light (in photography) or not given enough attention
Example
The photo was underexposed and looked too dark.
照片曝光不足，看起来太暗了。
C1 adjective /ʌnˈsɪvəl/

Uncivil

不文明的; 粗鲁的;
Meaning
not polite or courteous; rude and discourteous in behavior
Example
His uncivil remarks during the meeting offended everyone present.
他在会议上的不文明言论冒犯了在场的每一个人。
B1 adverb /ʌnˈjuːʒuəli/

unusually

异常地
Meaning
in a way that is not typical or expected; to an uncommon degree
Example
It was unusually cold for this time of year.
对一年中的这个时候来说，天气异常寒冷。
C1 adjective /ʌnˈvɔɪst/

unvoiced

未表达
Meaning
not expressed in speech; in phonetics, a sound produced without vocal cord vibration
Example
The student kept her opinion unvoiced during the meeting.
学生在会议期间保持她的意见未表达。
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.
B2 adjective /ˌʌnəˈfɪʃ.əl/

Unofficial

非官方的
Meaning
not officially authorized or confirmed; informal
Example
The unofficial results showed a close race.
非官方的结果显示出一场激烈的比赛。
C1 adjective /ˌʌndərˈhændɪd/

underhanded

阴险
Meaning
acting or done in a dishonest or secret way
Example
They exposed the company's underhanded dealings with its suppliers.
他们揭露了公司与供应商之间的隐秘交易。
C2 adjective /ʌnˈælɔɪd/

unalloyed

纯净
Meaning
Pure, complete, and not mixed with anything else.
Example
She felt unalloyed joy at the news of her success.
她听到成功的消息时感到纯粹的喜悦。
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 /ʌnˈfɔːltərɪŋ/

unfaltering

坚定不移
Meaning
Steady and resolute; not weakening or hesitating
Example
She continued with unfaltering determination.
她以坚定不移的决心继续前进。
C1 adjective /ʌnˈkuːθ/

uncouth

粗鲁
Meaning
Lacking good manners, refinement, or grace; awkward or rough.
Example
His uncouth behavior shocked the guests at the party.
他粗鲁的行为让聚会上的客人感到震惊。
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。
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。
B2 adverb /ʌnˈdaʊtɪdli/

undoubtedly

毫无疑问
Meaning
without a doubt, certainly
Example
He is undoubtedly the best player on the team.
他毫无疑问是队里最好的球员。
C1 verb /ˌʌndərˈvæljuː/

undervalue

低估
Meaning
To assign too low a value or importance to something or someone.
Example
She felt that her boss consistently undervalued her contributions.
她感觉到她的老板总是低估她的贡献。
C1 adjective /ˌʌnɪˈkwɪvəkəl/

unequivocal

明确
Meaning
Leaving no doubt; clear and unambiguous
Example
She gave an unequivocal answer to the question.
她对问题给出了明确的回答。
C1 adjective ʌnɪnˈhæbɪtəbəl

uninhabitable

不可居住
Meaning
Not suitable or safe for people to live in.
Example
Rapid urbanization can make cities uninhabitable.
快速城市化可能使城市变得无法居住。
C1 noun /ˈʌndərˌstʌdi/

understudy

替身演员
Meaning
An actor who learns another's role to act as a replacement if needed.
Example
The understudy performed when the lead actor fell ill.
当主角生病时，替身演员上场表演。
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。
B2 adjective /ˈʌpˌraɪt/

Upright

诚实且道德正确；垂直或挺立的姿势
Meaning
honest and morally correct; vertical or erect in position
Example
She is known for being an upright and honest businesswoman.
她以诚实和正直的商业女性而闻名。