Unconditional
All a b c d e f g h i j k l m n o p q r s t u v w x y z
All CEFR A1 A2 B1 B2 C1 C2
Content locale
EN 英语 BN 孟加拉语 HI 印地语 ES 西班牙语 FR 法语 DE 德语 RU 俄语 ZH 中文 JA 日语
All Vocabulary Cards All Vocabularies
B2 adjective /ʌnˌkənˈdɪʃ.ən.əl/

Unconditional

无条件的
Meaning
not subject to any conditions; complete and absolute
Example
She offered her unconditional support to her friend in need.
她在朋友需要时提供了无条件的支持。
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。
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。
C2 adjective ˌʌn.əˈseɪ.lə.bəl

unassailable

不可攻破
Meaning
Unable to be attacked, questioned, or defeated.
Example
An unassailable position ensures dominance.
不可攻破的位置确保主导地位。
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。
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。
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。
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。
B2 adjective /ˌʌnrɪˈlaɪəbl/

Unreliable

不可靠的; 不能被信任或依赖
Meaning
not dependable; not able to be trusted or relied upon
Example
The old car is unreliable and breaks down frequently.
这辆老车不可靠，常常坏掉。
B2 adverb /ʌnˈsɜːrtənli/

uncertainly

不确定地
Meaning
in a way that shows doubt or lack of certainty
Example
She glanced uncertainly at the complicated instructions.
她不确定地看着复杂的说明。
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 /ʌnˈmɒdɪfaɪd/

unmodified

未修改的
Meaning
not changed from its original form or state
Example
The data was used in its unmodified form for analysis.
这些数据以未修改的形式用于分析。
B2 adjective /ʌnˈberəbəl/

Unbearable

无法忍受
Meaning
too painful, annoying, or unpleasant to tolerate; impossible to endure
Example
The heat in the desert was unbearable.
沙漠中的热度是无法忍受的。
C1 adjective /ˌjuːnɪˈlætərəl/

Unilateral

单方面
Meaning
one-sided; involving only one party
Example
The country made a unilateral decision to withdraw from the treaty.
这个国家做出了单方面的决定，退出了条约。
B2 noun /ʌnˈsɜːrtənti/

Uncertainty

不确定性; 怀疑或缺乏确信
Meaning
the state of being uncertain; doubt or lack of sureness
Example
The uncertainty about the weather delayed our trip.
关于天气的不确定性延迟了我们的旅行。
B2 noun ˌjuːtɪlaɪˈzeɪʃən

utilization

利用
Meaning
The action of making practical and effective use of something.
Example
Increased plastic utilization calls for better waste management.
塑料的使用增加要求更好的废物管理。
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。
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 /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。
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。
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。
B2 adjective /ˈʌt.moʊst/

Utmost

最极; 极限
Meaning
greatest; most extreme; maximum possible
Example
She showed utmost care while handling the fragile items.
她在处理脆弱物品时表现出最大的关心。
C1 adjective /ˌʌnəbˈtruːsɪv/

unobtrusive

不引人注目
Meaning
not attracting attention; blending in without causing notice
Example
The security cameras are designed to be unobtrusive.
安全摄像头被设计成不引人注目。
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 adjective /ʌnˈtʃeɪst/

Unchaste

不道德的; 不纯洁的;
Meaning
not celibate; having engaged in sexual relations; lacking moral purity
Example
The conservative society considered her behavior unchaste and improper.
保守的社会认为她的行为不道德和不合适。
C1 adjective /ʌnˈtʃælɪndʒd/

Unchallenged

无可争议的; 被接受的没有反对; 没有对手
Meaning
not disputed or questioned; accepted without opposition; having no rival
Example
He remained the unchallenged champion for five years.
他五年保持不败的冠军。
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。
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。
A2 adjective /ʌnˈtaɪdi/

Untidy

凌乱的; 无序的;
Meaning
not neat or orderly; messy and disorganized
Example
Her untidy room was filled with clothes scattered everywhere.
她凌乱的房间充满了四处散落的衣服。
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。
C2 adjective /ʌpˈrɔːr.i.əs/

uproarious

极其滑稽
Meaning
Extremely funny or noisy; causing loud laughter or commotion.
Example
The comedian's jokes were absolutely uproarious.
喜剧演员的笑话绝对是极其滑稽的。
B1 adjective /ˌʌnɪkˈspektɪd/

Unexpected

出乎意料的; 令人惊讶的
Meaning
not expected or anticipated; surprising
Example
The unexpected news left everyone speechless.
出乎意料的消息让所有人都哑口无言。
B1 adjective /ʌnˈkaʊntəbəl/

Uncountable

无法计数的; 无穷的
Meaning
too many to be counted; innumerable; infinite in quantity
Example
There are uncountable stars in the night sky.
夜空中有无数的星星。
C2 adjective /ʌnˈtɛmpərd/

untempered

失控的
Meaning
not moderated or softened; lacking proper balance or control
Example
The untempered anger of the crowd caused chaos.
人群的失控愤怒引发了混乱。
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。
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。
C2 adjective /ˌʌn.təˈwɔːrd/

untoward

意外的
Meaning
Unexpected and inappropriate or inconvenient.
Example
The meeting ended without any untoward incidents.
会议在没有任何意外事件的情况下结束。
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。
A1 pronoun /ʌs/

us

我们
Meaning
used to refer to the speaker and one or more other people as the object of a verb or preposition
Example
She gave us a gift.
她给了我们一个礼物。
B1 adjective /ˌʌnɪmˈpɔːrtənt/

unimportant

不重要的
Meaning
not having much value, significance, or influence
Example
The detail seemed unimportant compared to the main issue.
与主要问题相比，这个细节显得不重要。
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。
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。
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。
B2 adjective /ˌʌndɪˈstɜːrbd/

Undisturbed

未打扰
Meaning
not interrupted or interfered with; calm and peaceful
Example
She slept undisturbed for eight hours.
她睡了八个小时没有打扰。
B1 adverb /ʌnˈfɔːrtʃənətli/

Unfortunately

不幸地
Meaning
used to express regret or disappointment about something
Example
Unfortunately, the weather was bad for our picnic.
很遗憾，天气不适合我们的野餐。
B1 adjective /ʌnˈkaɪnd/

Unkind

残忍; 不友好
Meaning
cruel; not nice or caring toward others
Example
It was unkind of him to make fun of her appearance.
他取笑她的外貌，真是太不友善了。
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。
A1 verb /juːz/

use

使用
Meaning
to employ something for a purpose; to take advantage of
Example
I use my computer for work and entertainment.
我用我的计算机来工作和娱乐。
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。
C1 adjective ʌnˈjiːl.dɪŋ

unyielding

坚定或坚韧
Meaning
Not easily broken or giving in to pressure.
Example
Her unyielding determination helped her overcome all challenges.
她坚定的决心帮助她克服了所有的挑战。
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。
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 adverb /ˈʌltəmətli/

ultimately

最终
Meaning
in the end, after everything else
Example
Ultimately, we decided to go ahead with the project.
最终，我们决定继续推进该项目。
C2 adjective /ʌkˈsɔːriəs/

uxorious

过度宠爱妻子
Meaning
excessively fond of or submissive to one's wife
Example
He was so uxorious that he agreed with everything his wife said.
他是如此的宠爱妻子，以至于同意了妻子说的每一件事。
B2 adjective /ʌnˈbreɪkəbəl/

Unbreakable

不能被打破或损坏；非常强大和耐用
Meaning
not able to be broken or damaged; very strong and durable
Example
Their friendship formed an unbreakable bond.
他们的友谊形成了一个坚不可摧的纽带。
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 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 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。
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 /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 noun /ʌnəˈbɪləti/

unability

无能
Meaning
the state of being unable to do something; incapacity
Example
His unability to solve the problem caused delays in the project.
他解决问题的无能导致了项目的延误。
B2 adjective /ʌnˈtʃeɪndʒɪŋ/

unchanging

不变的
Meaning
remaining the same over time; not changing
Example
Her love for her family was unchanging throughout the years.
她对家人的爱多年来始终不变。
C2 noun /ˌjuːnɪˈtɛəriən/

unitarian

一神论者
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.
一神论教会以其包容和开放的思想方式而闻名。
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。
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。
B2 adjective /ʌnˈsteɪbəl/

Unstable

不稳定
Meaning
likely to change; not steady or secure; unsteady
Example
The unstable economy made people worried about their jobs.
不稳定的经济让人们担心他们的工作。
C2 noun /juːˌtɪlɪˈtɛəriənɪzəm/

utilitarianism

功利主义
Meaning
The ethical theory that actions are right if they are useful or for the benefit of the majority.
Example
Utilitarianism suggests that we should act to maximize overall happiness.
功利主义认为我们应该采取行动，以最大化整体幸福。
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。
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。
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 verb /ˌʌndərˈteɪk/

undertake

承担
Meaning
to commit to and begin a task or project; to take on responsibility
Example
She decided to undertake a challenging project.
她决定承担一个具有挑战性的项目。
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。
C1 adjective /ˈʌndərhænd/

underhand

阴险
Meaning
done secretly and dishonestly; deceitful
Example
The politician was accused of using underhand tactics to win the election.
那位政治家被指控使用阴险的手段赢得选举。
B1 adjective /ʌnˈlaɪk/

Unlike

不同的; 不相似的
Meaning
different from; not similar to
Example
Unlike his brother, he prefers quiet activities.
与他哥哥不同，他喜欢安静的活动。
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。
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 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。
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 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。
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。
B2 adjective /ʌnhaɪˈdʒiːnɪk/

Unhygienic

不卫生的；缺乏适当的卫生
Meaning
not clean; lacking proper sanitation
Example
The restaurant was closed due to unhygienic conditions in the kitchen.
由于厨房不卫生的条件，餐厅被关闭。
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。
C1 adjective /ʌnˈtʌtʃəbəl/

Untouchable

不可触碰的; 无法批评或攻击
Meaning
not able to be touched or affected; beyond criticism or attack
Example
The CEO seemed untouchable despite the scandal.
即使有丑闻，首席执行官似乎仍然是不可触碰的。
A1 interjection /ʌ/

uh

呃
Meaning
a sound people make when they hesitate or are unsure what to say next.
Example
Uh, I’m not sure if that’s the right answer.
呃，我不确定这是不是正确的答案。
B1 adjective /ʌnˈnoʊn/

Unknown

未知
Meaning
not known or identified; unfamiliar
Example
The author of this letter remains unknown.
这封信的作者仍然未知。
C1 adjective /ˌʌnˈɪntɪmeɪtɪŋ/

unintimating

没有暗示
Meaning
Not giving a hint or suggestion; not indicating.
Example
His unintimating tone gave no clue of his true feelings.
他的没有暗示的语气没有透露他真正的感受。
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。
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。
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。
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。
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。
B1 adjective /ʌnˈjuzd/

Unused

未使用的; 没有被使用
Meaning
not being used; not having been used before
Example
There are many unused rooms in this old mansion.
这个古老的豪宅里有许多未使用的房间。
B1 noun /juːˈten.səlz/

Utensils

餐具
Meaning
tools or implements used for cooking, eating, or serving food
Example
Please wash all the cooking utensils after preparing dinner.
请在准备晚餐后清洗所有的厨房用具。
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。
A2 noun /ˈʌndərwɛr/

Under wear

内衣
Meaning
clothing worn under other clothes, next to the skin
Example
She bought new underwear from the department store.
她在百货商店买了新的内衣。
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 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.
B2 verb ˈjuːnɪfaɪ

unify

统一
Meaning
To make or become united, uniform, or whole; to bring together into a single unit.
Example
Adolescents unify with peers for social acceptance.
青少年为了社会接纳与同伴统一。
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。
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 adjective /ˌʌnəˈteɪnəbl/

unattainable

无法实现的
Meaning
impossible to achieve, reach, or accomplish
Example
For many, becoming a professional athlete remains an unattainable dream.
对许多人来说，成为职业运动员仍然是一个无法实现的梦想。
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。
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 adjective /ˌʌnrɪˈzɒlvd/

unresolved

未解决的
Meaning
not solved or settled; remaining undecided or unclear
Example
The dispute remains unresolved despite several meetings.
尽管开了几次会议，这个争议仍未解决。
B2 adjective /ʌnˈtʃeɪndʒəbəl/

Unchangeable

不可改变的; 固定的;
Meaning
not able to be changed or altered; fixed and permanent
Example
The laws of physics are unchangeable principles that govern the universe.
物理法则是不变的原则，支配着宇宙。
C1 noun /ˈʌp.ʃɒt/

Upshot

结果; 结论
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.
会议的结果是决定推迟项目。
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 /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。
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 /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 /ˌʌnɪnˈhɪbɪtɪd/

uninhibited

不受抑制的
Meaning
Not restrained or restricted; free in behavior or expression.
Example
She gave an uninhibited laugh at the joke.
她在笑话中放声大笑。
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。
A2 noun /ˈjuːnɪt/

unit

单元
Meaning
an individual thing or person regarded as a single and complete entity
Example
Each unit in the production line is carefully tested.
生产线上的每个单元都经过仔细测试。
B2 adjective /ʌnˈbaɪəst/

unbiased

公正
Meaning
Not showing prejudice; impartial and fair.
Example
The report gave an unbiased view of the situation.
报告提供了该情况的公正观点。
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 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。
C2 adjective /ˌʌnpriːpəˈzɛsɪŋ/

unprepossessing

不吸引人
Meaning
not attractive or appealing in appearance
Example
Despite his unprepossessing looks, he was very kind and intelligent.
尽管他的外貌不吸引人，他还是非常友善和聪明。
B1 adjective /ʌnˈseɪf/

Unsafe

不安全; 危险的;
Meaning
involving or causing danger or risk; not protected from harm
Example
It is unsafe to walk alone in this neighborhood at night.
晚上在这个社区独自行走是不安全的。
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 /ˌʌnprɪˈdɪktəˌbɪləti/

unpredictability

不可预测性
Meaning
The quality of being impossible to predict or anticipate.
Example
The unpredictability of the weather made the trip uncertain.
天气的不可预测性使得旅行充满不确定性。
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。