Outline
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 noun /ˈaʊt.laɪn/

Outline

大纲; 轮廓; 摘要
Meaning
a general description or plan showing the essential features of something; the main points
Example
The teacher provided an outline of the course syllabus.
老师提供了课程大纲。
A1 adverb /ɔːf/

off

关
Meaning
away from a place, position, or time; not functioning
Example
He turned off the light before leaving the room.
他在离开房间之前关掉了灯。
B2 adjective /ˈɒp.ʃən.əl/

Optional

可选的
Meaning
not compulsory; left to choice
Example
Wearing a tie is optional for this event.
穿领带是这个活动的可选项。
C1 adjective /ˈɑp.ər.ə.tɪv/

Operative

有效的; 运行中的; 工作中的; 操作性的;
Meaning
Functioning; in effect; working; active;
Example
The new safety protocols became operative immediately after the accident.
新的安全协议在事故发生后立即生效。
C2 noun /ˈoʊɡər/

ogre

Meaning
A mythical monster, often depicted as large, hideous, and cruel; metaphorically, a cruel or terrifying person.
Example
The villagers feared the ogre who lived in the dark forest.
C2 noun /ˈoʊ.vər.let/

Overlet

床垫
Meaning
a thin mattress or pad placed over a bed for additional comfort
Example
The overlet makes the bed more comfortable to sleep on.
欧弗雷特使床铺更适合睡觉。
B2 noun ɔːˈɡæn.ɪk fuːdz

organic foods

有机食品
Meaning
Food produced without the use of chemicals such as artificial pesticides, fertilizers, or other artificial agents.
Example
Organic foods are healthier than processed foods.
有机食品比加工食品更健康。
B2 noun /ˈoʊvərpæs/

overpass

立交桥
Meaning
A bridge that carries one road or railway over another.
Example
The new overpass reduced traffic congestion in the city.
新的立交桥减少了城市的交通拥堵。
A1 adjective /oʊˈkeɪ/

ok

好的
Meaning
used to indicate agreement, approval, or understanding
Example
Okay, let's go to the park.
好的，我们去公园。
C1 noun /ˌɑːk.sɪˈmɔːr.ɒn/

oxymoron

矛盾修饰法
Meaning
a figure of speech where two contradictory terms are combined
Example
The phrase 'deafening silence' is a classic oxymoron.
短语 '震耳欲聋的寂静' 是一个经典的矛盾修饰法。
B2 adjective /aʊtˈstændɪŋ/

outstanding

杰出
Meaning
extremely good or impressive; not yet resolved or paid
Example
She received an award for her outstanding performance.
她因出色的表现获得了奖项。
A1 pronoun /aʊərz/

ours

我们的
Meaning
belonging to or associated with us
Example
This victory is ours.
这个胜利是我们的。
B2 noun oʊˈbiː.sə.t̬i

obesity

肥胖症
Meaning
The condition of being grossly fat or overweight.
Example
Obesity increases the risk of diabetes and heart disease.
肥胖症增加糖尿病和心脏病的风险。
B2 adverb /ˈəʊvəli/

overly

过度
Meaning
to an excessive degree or extent
Example
She was overly concerned about the results.
她对结果过于担忧。
C1 adjective /ˈaʊt.kɑːst/

Outcast

被排斥的人
Meaning
rejected by society; excluded person
Example
He felt like an outcast in his new school.
他在新学校里感觉自己像一个被排斥的人。
B2 adjective /ˈaʊtˌɡoʊɪŋ/

outgoing

外向
Meaning
Friendly and sociable; inclined to mix with others.
Example
He is an outgoing person who loves meeting new people.
他是一个外向的人，喜欢结识新朋友。
B2 noun /ˈoʊtˌmiːl/

oatmeal

燕麦粥
Meaning
A type of porridge made from ground oats, often eaten for breakfast.
Example
She eats a bowl of oatmeal every morning for breakfast.
她每天早晨吃一碗燕麦粥当早餐。
A2 noun /ˈɔr.dər/

Order

命令; 顺序
Meaning
a command or instruction; the arrangement of things following a particular sequence
Example
The teacher gave an order to sit down quietly.
老师下达了安静坐下的命令。
C1 verb /ˌoʊvərˈθroʊ/

overthrow

幸福
Meaning
To remove a leader or government from power, often by force.
Example
The rebels planned to overthrow the corrupt regime.
她在收到奖项时无法掩饰她的幸福感。
C2 noun /ˌɒktədʒəˈnɛəriən/

octogenarian

八十岁老人
Meaning
A person who is between 80 and 89 years old.
Example
The octogenarian still jogs every morning to stay healthy.
这位八十岁老人仍然每天早上跑步以保持健康。
C1 adjective /oʊˈbiːs/

obese

肥胖
Meaning
Extremely overweight; having an excessive amount of body fat.
Example
The doctor advised the obese patient to adopt a healthier lifestyle.
医生建议肥胖的病人采取更健康的生活方式。
C1 verb ˈɔː.kɪ.streɪ.tɪd

orchestrated

精心策划
Meaning
Planned or coordinated carefully and deliberately.
Example
The attacks were orchestrated with precision.
袭击被精确地策划了。
C1 adjective /əbˈstrʌk.tɪv/

Obstructive

阻碍性的
Meaning
deliberately creating difficulties or preventing progress; hindering or blocking something
Example
The obstructive policies hindered economic growth.
这些阻碍性的政策阻碍了经济增长。
B2 noun /ˈɒt.ər/

Otter

水獺
Meaning
a mammal with webbed feet that lives near water and feeds on fish
Example
The playful otter swam gracefully in the river.
顽皮的水獺优雅地在河里游泳。
C2 noun /ˈɔːrɪndʒfɪn ˈleɪbiːoʊ/

Orangefin labeo

橙鳍鲤
Meaning
a freshwater fish species native to South Asian rivers, commonly found in Bangladesh and India
Example
The orangefin labeo is an important food fish in Bangladesh.
橙鳍鲤是孟加拉国重要的食用鱼。
C2 noun /ˈoʊpiət/

opiate

Meaning
a drug containing opium or its derivatives, used to relieve pain or cause sleep
Example
The doctor prescribed an opiate to relieve the patient's pain.
B2 noun /oʊˈbiː.di.əns/

Obedience

服从
Meaning
compliance with an order, request, or law; submission to authority
Example
Children should show obedience to their parents.
孩子们应该对父母表现出服从。
B2 adjective /aʊtˈreɪdʒəs/

outrageous

骇人听闻
Meaning
Shockingly bad or excessive; very unusual or amusing.
Example
The comedian told an outrageous joke.
这位喜剧演员讲了一个骇人听闻的笑话。
B2 adverb /əˈfɪʃəli/

officially

正式地
Meaning
in a formal or authorized way
Example
The building was officially opened by the mayor.
这座建筑由市长正式开幕。
B2 noun /ˌɒpəˈzɪʃən/

opposition

反对
Meaning
the action of opposing or resisting something
Example
The opposition to the new law was strong.
对新法律的反对很强烈。
C1 adjective /əbˈtjuːs/

Obtuse

迟钝的; 愚笨的; 理解慢
Meaning
annoyingly insensitive or slow to understand; lacking in intelligence or perception
Example
He was being deliberately obtuse about the instructions.
他故意在指令上表现得迟钝。
C2 adjective /ˈɒfɪʃ/

offish

冷淡
Meaning
Unfriendly, distant, or reserved in manner.
Example
He seemed offish at the party and avoided most conversations.
他在派对上显得很冷淡，避开了大多数谈话。
B2 verb /ɒpt/

opt

选择
Meaning
to choose or decide to do something instead of something else
Example
Many students opt to study abroad for better opportunities.
许多学生选择出国留学以获得更好的机会。
C2 noun /ˈɑːbəlɪsk/

obelisk

方尖碑
Meaning
A tall, four-sided, narrow tapering monument with a pyramid-shaped top.
Example
The ancient Egyptians built obelisks to honor their gods.
古埃及人建造了方尖碑来纪念他们的神。
C1 noun /əˈkɜr.əns/

Occurrence

事件
Meaning
an instance or event of something happening; the fact of occurring
Example
The occurrence of earthquakes is common in this region.
地震的发生在这个地区很常见。
B2 adjective /ˈɒp.tɪ.məl/

optimal

最优，最适合的
Meaning
Best or most favorable; the most effective under particular conditions.
Example
The optimal temperature for plant growth is around 25°C.
植物生长的最优温度大约是25°C。
B1 noun /ˈɔr.ə.ʒɪn/

Origin

起源
Meaning
the point or place where something begins, arises, or is derived; the source
Example
Scientists are studying the origin of the universe.
科学家正在研究宇宙的起源。
A2 noun əˈlɪm.pɪk ɡeɪmz

Olympic Games

奥林匹克运动会
Meaning
The world's largest international sports competition held every four years, bringing together athletes from different countries to compete in various sports.
Example
The Olympic Games bring together the world's top athletes.
奥林匹克运动会汇聚了世界上最顶尖的运动员。
C1 adjective /ɒˈstɛnsəbl/

ostensible

表面上
Meaning
stated or appearing to be true, but not necessarily so
Example
His ostensible reason for leaving was illness, but many doubted it.
他离开的表面上原因是生病，但许多人对此表示怀疑。
C1 verb /ˈɒp.tɪ.maɪz/

optimize

优化
Meaning
To make the best or most effective use of a situation, opportunity, or resource.
Example
The company is working to optimize its supply chain.
公司正在努力优化其供应链。
A1 pronoun, noun, adjective /wʌn/

one

一
Meaning
the number equivalent to the sum of zero and one; a single person or thing
Example
Only one student answered the question.
只有一个学生回答了问题。
B2 adverb /ˈɒdli/

oddly

奇怪地
Meaning
in a strange or unusual way; unexpectedly
Example
Oddly, he didn’t seem upset by the bad news.
奇怪的是，他似乎并没有因为坏消息而难过。
C1 noun/verb /ˈoʊvərˌhæŋ/

overhang

悬垂
Meaning
To extend outward and hang over something; a projecting part.
Example
The roof overhang provides shade in the summer.
屋顶的悬垂部分在夏天提供阴凉。
A1 adverb /aʊt/

out

外面
Meaning
moving or appearing away from the inside or center; not at home or present
Example
He stepped out of the room quietly.
他悄悄地走出房间。
A1 verb, adjective /oʊn/

own

拥有
Meaning
to possess something; belonging to oneself
Example
She owns a beautiful house in the city.
她拥有一座漂亮的房子。
C2 adjective /ɒmˈnɪp.ə.tənt/

omnipotent

全能
Meaning
Having unlimited power; able to do anything; all-powerful.
Example
In many religions, God is considered omnipotent.
在许多宗教中，上帝被认为是全能的。
C1 noun əˈblɪv.i.ən

oblivion

遗忘, 灭绝, 消失
Meaning
The state of being unaware or unconscious of what is happening; complete forgetfulness.
Example
His name faded into oblivion over time.
随着时间的推移，他的名字渐渐消失在遗忘中。
C1 noun /ˌoʊvərprəˈdʌkʃən/

overproduction

过度生产
Meaning
The act of producing more of something than is needed or can be consumed.
Example
The economic crisis was caused by the overproduction of goods.
经济危机是由商品的过度生产引起的。
C1 noun /ɔːr/

Oar

桨
Meaning
a long pole with a flat blade used to row a boat
Example
He dipped the oar into the water and pulled the boat forward.
他将桨浸入水中并拉动船向前。
B1 noun /əˈpɪn.jən/

Opinion

意见
Meaning
a view or judgment formed about something; a belief or assessment based on grounds short of proof
Example
In my opinion, this is the best solution.
在我看来，这是最好的解决方案。
A2 adverb /ˈɒbviəsli/

obviously

显然
Meaning
in a way that is easily perceived or understood; clearly
Example
Obviously, he didn’t read the instructions.
显然，他没有读说明书。
C1 noun /əbˈzɜːrvətɔːri/

observatory

天文台
Meaning
A building equipped for observing astronomical or meteorological events.
Example
The observatory is open to the public on weekends.
天文台在周末对公众开放。
C1 verb /əbˈsɛs/

obsess

Meaning
To preoccupy or fill the mind of someone continually and to an excessive degree.
Example
She tends to obsess over small details.
C1 adjective /ˈəʊnərəs/

onerous

繁重
Meaning
involving a great deal of effort, difficulty, or burden
Example
Fulfilling the contract proved to be an onerous task for the company.
履行合同对公司来说是一项繁重的任务。
B2 noun /ˈɔːrnəmənt/

ornament

装饰品
Meaning
A decorative object that adds beauty to something.
Example
The Christmas tree was decorated with colorful ornaments.
圣诞树上装饰着五颜六色的装饰品。
C1 verb /ˈoʊvərˌhɔːl/

overhaul

全面改革
Meaning
to examine thoroughly and repair or improve something that is worn or ineffective
Example
The company decided to overhaul its outdated computer system.
公司决定彻底改革其过时的计算机系统。
B1 noun /ˌɒp.əˈtjuː.nə.ti/

opportunity

机会
Meaning
A favorable chance or set of circumstances that makes it possible to do something.
Example
She seized the opportunity to study abroad.
她抓住了去国外学习的机会。
C1 verb /ˌoʊvərˈruːl/

overrule

驳回
Meaning
to reject or disallow by exercising one's superior authority; to override a decision
Example
The judge overruled the objection from the defense attorney.
法官驳回了辩护律师的反对。
C2 noun /ˈɒbsɪkwi/

obsequy

葬礼仪式
Meaning
A funeral rite, usually used in plural form obsequies.
Example
The village gathered for the obsequy of their beloved teacher.
村庄聚集在一起，参加他们心爱的老师的葬礼。
C1 noun /ˈoʊvərˌsiːər/

overseer

监督员
Meaning
a person who supervises work or workers; a manager
Example
The overseer made sure the workers followed safety rules.
监督员确保工人遵守安全规则。
B2 noun ˈɔː.bɪt

orbit

轨道
Meaning
The curved path of a celestial object around a star, planet, or moon.
Example
The satellite maintains its orbit around Earth.
卫星保持它绕地球的轨道。
C1 adjective /oʊˈvɜːrt/

overt

公开的
Meaning
Done or shown openly; not hidden or secret.
Example
There was an overt display of hostility between the rivals.
在对手之间有一种公开的敌意表现。
C1 adjective /aʊtˈmoʊdɪd/

outmoded

过时的
Meaning
No longer in fashion or useful; outdated.
Example
That old computer is completely outmoded.
那台旧电脑完全过时了。
C2 adjective /ɒˈstɛnsɪv/

ostensive

显性
Meaning
clearly demonstrative or pointing out; explicitly shown
Example
The teacher gave an ostensive example to clarify the concept.
老师举了一个显性的例子来阐明概念。
B2 noun /əbˈdʒek.ʃən/

Objection

反对; 异议; 抗议;
Meaning
an expression of disagreement or disapproval; a reason for disagreeing
Example
The lawyer raised an objection during the trial.
律师在审判过程中提出了异议。
C1 noun /ˈɑːlɪˌɡɑːrki/

oligarchy

寡头政治
Meaning
A small group of people having control of a country, organization, or institution.
Example
The nation was ruled by a wealthy oligarchy that controlled all resources.
这个国家由一个富有的寡头集团统治，控制着所有资源。
C2 noun /ˈɒb.stɪ.nə.si/

obstinacy

固执
Meaning
Stubborn refusal to change one's opinion or chosen course of action, despite attempts to persuade one to do so.
Example
His obstinacy made negotiations difficult.
他的固执使谈判变得困难。
C2 noun /ˈɒfərtɔːri/

offertory

奉献
Meaning
The part of a religious service when offerings are collected; the offering itself.
Example
The offertory was taken during the Sunday service.
奉献在星期日的礼拜期间收集。
B2 noun /ˈɔr.fən.ɪʒ/

Orphanage

孤儿院
Meaning
an institution for the care and education of children who have lost their parents
Example
The charity built a new orphanage for homeless children.
慈善机构为无家可归的孩子建了一个新孤儿院。
C2 adjective /ˈɒf.biːt/

offbeat

不寻常
Meaning
Unusual, unconventional, or different from the norm.
Example
She has a very offbeat sense of humor.
她有非常不寻常的幽默感。
C1 noun /ˈɔːrdɪnəns/

ordinance

法令
Meaning
An authoritative rule, law, or decree issued by a city, town, or authority.
Example
The city council passed an ordinance banning smoking in public parks.
市议会通过了一项法令，禁止在公共公园内吸烟。
C2 verb /ˌaʊtməˈnuːvər/

outmaneuver

巧妙地战胜
Meaning
to gain an advantage over an opponent by skillful or clever action
Example
The smaller company managed to outmaneuver its larger rival.
小公司成功地战胜了它的大对手。
A1 preposition, adverb /ˈoʊvər/

over

在…上面
Meaning
across, on top of, or beyond
Example
The book is lying over the table.
书在桌子上面。
B2 noun /ˌɑb.zɚˈveɪ.ʃən/

Observation

观察
Meaning
the action of watching something carefully; a comment or remark
Example
The scientist made careful observations of the experiment.
科学家仔细观察了实验。
B2 verb /ˌoʊvərˈiːt/

overeat

幸福
Meaning
To eat more food than the body needs.
Example
She tends to overeat when she is stressed.
她在收到奖项时无法掩饰自己的幸福。
A1 adjective /ˈɔːr.ɪndʒ/

Orange

橙色
Meaning
having a color between red and yellow like that of a ripe orange fruit
Example
The orange sunset painted the sky magnificently.
橙色的日落把天空画得非常壮丽。
B1 noun ˌɔː.ɡən.aɪˈzeɪ.ʃənz

organizations

组织
Meaning
Organized groups of people with a particular purpose
Example
Organizations play a key role in policymaking.
组织在政策制定中发挥着重要作用。
C2 adjective /ˌɒbsəˈlɛsnt/

obsolescent

过时的
Meaning
Becoming outdated or on the way to becoming obsolete.
Example
The obsolescent technology could not compete with modern devices.
过时的技术无法与现代设备竞争。
B1 noun /ˌɑk.jəˈpeɪ.ʃən/

Occupation

职业; 工作; 占领
Meaning
a job or profession; the action of taking control of a place
Example
Teaching is her chosen occupation.
教学是她选择的职业。
B1 noun /ˈɒbstəkəlz/

obstacles

障碍
Meaning
Things that block one's way or prevent or hinder progress.
Example
Obstacles in life can often lead to valuable lessons.
生活中的障碍常常导致宝贵的教训。
B2 noun ˈɒksɪdʒən prəˈdʌkʃən

oxygen production

氧气生产
Meaning
The process of generating oxygen through photosynthesis or other means.
Example
Plants are vital for oxygen production and the maintenance of life.
植物对于氧气生产和维持生命至关重要。
A1 interjection /oʊ/

oh

哦
Meaning
used to express surprise, realization, or understanding
Example
Oh, I didn't know you were here!
哦，我不知道你在这里！
C1 verb /ˌoʊvərˈʃædoʊ/

overshadow

掩盖
Meaning
to appear more important or significant than something else, reducing its impact
Example
The scandal overshadowed his achievements.
丑闻掩盖了他的成就。
A2 noun /ˈoʊpənɪŋ/

opening

开幕
Meaning
an act or instance of beginning something
Example
The opening of the new store was a huge success.
新店的开业是一个巨大的成功。
C2 noun /oʊliˈændər/

Oleander

夹竹桃
Meaning
a poisonous evergreen shrub with clusters of white, pink, or red flowers
Example
The beautiful oleander flowers bloomed in the garden despite their toxic nature.
美丽的夹竹桃花在花园里盛开，尽管它们有毒。
B2 noun /ˈaʊtbɜːrst/

outburst

情感或活动的突然爆发
Meaning
a sudden release of strong emotion or activity
Example
She had an angry outburst during the meeting.
她在会议期间突然发火。
B2 verb /əˈblaɪdʒ/

oblige

迫使
Meaning
to compel or require someone to do something; to help or do a favor
Example
I would be happy to oblige you with the information you need.
我很乐意为你提供所需的信息。
C2 noun /ˈaʊtˌrɪɡər/

outrigger

稳定结构
Meaning
a projecting structure on a boat, used for stability, or a boat fitted with such support
Example
The fisherman paddled his outrigger canoe across the lagoon.
渔民划着带有支撑的独木舟穿过泻湖。
A1 adjective /əʊˈkeɪ/

okay

没问题
Meaning
used to express agreement or acceptance
Example
It's okay to leave early today.
今天早些离开没问题。
C1 adverb /ˈɒp.tɪ.məl.i/

optimally

最优地
Meaning
In the most effective or efficient way possible.
Example
Tasks should be allocated optimally for maximum output.
任务应当最优地分配，以实现最大产出。
C2 adjective /ˈoʊ.vɔɪd/

ovoid

卵形
Meaning
egg-shaped; resembling an oval or ellipse
Example
The artist painted an ovoid shape in the center of the canvas.
艺术家在画布中心画了一个卵形的形状。
B2 adjective /ˌɑːp.təˈmɪs.tɪk/

optimistic

乐观的
Meaning
hopeful and confident about the future
Example
She is optimistic about the success of her new project.
她对新项目的成功持乐观态度。
C1 verb /aʊtˈlɪv/

outlive

比…活得长
Meaning
to live longer than someone or something else
Example
She outlived all her siblings.
她活过了所有的兄弟姐妹。
C1 noun /ˈaʊtˌkraɪ/

outcry

抗议
Meaning
A strong expression of public anger or disapproval.
Example
The decision sparked an outcry among the citizens.
这个决定在市民中引发了抗议。
C1 noun ˌɒb.səˈlɛs.əns

obsolescence

淘汰
Meaning
The process of becoming obsolete or outdated and no longer used.
Example
The rapid advancement of technology leads to the obsolescence of old devices.
科技的快速发展导致旧设备的淘汰。
C1 verb /əˈprɛs/

oppress

压迫
Meaning
to keep someone down by harsh and unfair use of authority; to suppress
Example
The dictator oppressed the people for decades.
独裁者压迫人民数十年。
B2 verb /ˌoʊvərˈpeɪ/

overpay

支付过多
Meaning
To pay more than is necessary or reasonable.
Example
She realized she had overpaid for the concert tickets.
她意识到她为音乐会门票支付过多。
C1 noun ˈoʊʃən əˌsɪdɪfɪˈkeɪʃən

ocean acidification

海洋酸化
Meaning
The ongoing decrease in the pH of the Earth's oceans, caused by the absorption of carbon dioxide from the atmosphere.
Example
Ocean acidification is caused by atmospheric CO2 absorption.
海洋酸化是由大气中CO2的吸收引起的。
A1 adjective /ˈʌðər/

other

其他
Meaning
used to refer to something different from the one already mentioned or known
Example
I don't want this one, I will take the other one.
我不想要这个，我会拿另一个。
B2 noun /ˈaʊtˌfɪt/

outfit

服装
Meaning
A set of clothes worn together, often for a particular occasion.
Example
She wore a beautiful outfit to the party.
她穿了一套漂亮的服装去参加派对。
C1 adjective /ˌɔːrnəˈmɛntl/

ornamental

装饰性的
Meaning
Serving as decoration; decorative rather than functional.
Example
The garden was filled with ornamental plants.
花园里满是装饰性的植物。
C1 noun /ˈaʊtpoʊst/

outpost

前哨站
Meaning
A small military camp or position at some distance from the main force, used especially as a guard.
Example
The soldiers were stationed at a remote outpost.
士兵们被驻扎在一个偏远的前哨站。
B2 verb /ˌoʊvərˈkʌm/

overcome

克服
Meaning
To succeed in dealing with a problem or difficulty.
Example
You can overcome procrastination with planning.
你可以通过计划来克服拖延症。
C1 adjective /ˈɒptɪk/

optic

光学的
Meaning
Relating to the eye or vision.
Example
The optic nerve carries signals from the eye to the brain.
视神经将信号从眼睛传递到大脑。
C1 noun /ˈɔr.i.ənt/

Orient

东方，尤其是东亚国家
Meaning
the East, especially countries of eastern Asia; to determine one's position or direction
Example
Many spices come from the Orient.
许多香料来自东方。
C2 noun ˈoʊʃən ˌstrætɪfɪˈkeɪʃən

ocean stratification

海洋分层
Meaning
The formation of layers in ocean water due to differences in density.
Example
Ocean stratification affects marine biodiversity.
海洋分层影响海洋生物多样性。
B2 verb /əbˈteɪn/

obtain

获得
Meaning
to get or acquire something
Example
You need to obtain a visa before traveling abroad.
你需要在出国前获得签证。
C1 verb /ˌaʊtˈduː/

outdo

超越
Meaning
To do better than someone else; to surpass.
Example
She always tries to outdo her classmates in exams.
她总是尽力在考试中超越她的同学。
C2 adjective /ˈɑːbdjʊrət/

obdurate

固执
Meaning
Stubbornly refusing to change one's opinion or course of action.
Example
He remained obdurate despite everyone's pleas.
尽管大家的恳求，他依然固执。
C2 noun /ˈoʊ.kəm/

oakum

旧绳纤维
Meaning
loose fibers obtained by untwisting old ropes, used for caulking ships
Example
The shipbuilders used oakum to seal the gaps in the wooden planks.
造船工人使用欧卡姆来密封木板之间的缝隙。
C1 noun /ˌəʊvərɪksˌplɔɪˈteɪʃən/

overexploitation

过度开发
Meaning
The unsustainable use of natural resources at a rate that exceeds their ability to regenerate, leading to depletion and environmental degradation.
Example
Overexploitation of natural resources leads to environmental degradation.
过度开发自然资源会导致环境退化。
B1 noun /ˌɒpəˈreɪʃən/

operation

手术
Meaning
an act or process of functioning or operating
Example
The hospital performed a successful operation.
医院进行了成功的手术。
A2 noun /ˈoʊ.ʃən/

ocean

海洋
Meaning
A very large expanse of sea, especially the main areas of sea between continents.
Example
The ocean covers more than 70% of the Earth's surface.
海洋覆盖了地球表面超过70%。
C1 adjective /ˌaʊt əv ðə ˈweɪ/

out-of-the-way

偏远的或不寻常的
Meaning
remote or unusual; not in a convenient or usual location
Example
They stayed in an out-of-the-way village.
他们住在一个偏远的村庄里。
C1 adjective /ˌɒbsəˈliːt/

obsolete

过时的
Meaning
No longer in use or out of date.
Example
Floppy disks are now completely obsolete.
软盘现在完全过时了。
C2 noun (plural) /ˈɔːrdʒiːz/

orgies

狂欢
Meaning
Wild gatherings involving excessive indulgence in food, drink, or sexual activity.
Example
The ancient Romans were infamous for their lavish feasts and orgies.
古罗马人以其奢华的宴会和狂欢而闻名。
B2 noun /ˈɒp.tɪ.mɪ.zəm/

optimism

乐观
Meaning
Hopefulness and confidence about the future or the successful outcome of something.
Example
Her optimism helped her overcome difficult times.
她的乐观帮助她克服了困难的时光。
C2 adjective /əˈprəʊ.bri.əs/

opprobrious

侮辱性的
Meaning
Expressing strong criticism or scorn.
Example
He made opprobrious remarks about his opponent.
他对对手做出了侮辱性评论。
C2 noun /ˌɔːrəˈtɔːri.oʊ/

oratorio

宗教音乐作品
Meaning
A large-scale musical composition for orchestra, choir, and soloists, usually on a sacred theme, performed without costumes or scenery.
Example
Handel's 'Messiah' is one of the most famous oratorios ever written.
亨德尔的《弥赛亚》是最著名的宗教音乐作品之一。
C1 noun /ˈɑːdəsi/

odyssey

漫长的旅行
Meaning
a long, adventurous journey; a series of experiences
Example
Her career has been an odyssey of challenges and achievements.
她的职业生涯是一场挑战和成就的漫长旅行。
B2 noun /ˈɔːkɪstrə/

orchestra

管弦乐队
Meaning
a large group of musicians playing different instruments together
Example
The orchestra performed beautifully at the concert.
管弦乐队在音乐会上演奏得非常出色。