Oil
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
A2 noun /ɔɪl/

Oil

油
Meaning
a viscous liquid derived from petroleum or plants, used for cooking or fuel
Example
Heat the oil in a pan before adding the vegetables.
在加菜之前先把油加热。
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。
C1 noun /əˈfen.dər/

Offender

罪犯; 违法者
Meaning
a person who commits an illegal act; someone who breaks the law
Example
The young offender was sentenced to community service.
那个年轻的罪犯被判社区服务。
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 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 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。
B2 noun /əˈpoʊ.nənt/

Opponent

对手; 竞争者
Meaning
a person who disagrees with or resists a proposal or practice; someone who competes against another
Example
The chess player defeated his strongest opponent.
象棋选手击败了他最强的对手。
A1 pronoun /aʊər/

our

我们的
Meaning
belonging to or associated with the speaker and one or more other people
Example
This is our house.
这是我们的房子。
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。
C2 noun ˈɒpjʊləns

opulence

奢华
Meaning
Great wealth or luxuriousness.
Example
The opulence of the mansion was evident in its ornate furnishings.
大厦的奢华体现在其华丽的家具中。
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 noun /ˈaʊtˌbreɪk/

outbreak

爆发
Meaning
a sudden start or occurrence of something unpleasant, like disease or violence
Example
There was an outbreak of flu in the city.
城市中爆发了流感。
C1 noun /oʊˈveɪʃən/

ovation

掌声
Meaning
an enthusiastic show of approval, especially by clapping hands
Example
The actor received a standing ovation after his performance.
演员在表演后收到了站立的掌声。
C2 adjective /ˈɔːrəˌtʌnd/

orotund

深沉而清晰的声音
Meaning
full, rich, and clear in sound; pompous in style
Example
The actor's orotund voice filled the theater.
演员的深沉声音充满了剧院。
C1 noun /əˈpreʃ.ən/

Oppression

压迫; 虐待; 暴政;
Meaning
cruel or unjust treatment or exercise of authority; the state of being subject to harsh treatment
Example
The people fought against political oppression.
人民反对政治压迫而斗争。
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 /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。
A2 adverb; noun /ˌaʊtˈdɔːrz/

outdoors

在户外
Meaning
outside a building; the natural environment outside
Example
We spent the whole afternoon outdoors enjoying the fresh air.
我们整个下午都在户外享受新鲜空气。
C1 noun ˌɒp.tɪ.maɪˈzeɪ.ʃən

optimization

优化
Meaning
Improving processes to increase performance and efficiency.
Example
SEO optimization helps websites rank higher on search engines.
SEO优化帮助网站在搜索引擎中排名更高。
C1 adjective /ˌoʊvərˈbɛrɪŋ/

overbearing

专横
Meaning
unpleasantly or arrogantly domineering
Example
His overbearing attitude made everyone uncomfortable.
他的专横态度让所有人都感到不舒服。
B1 noun /ˈɑb.stə.kəl/

Obstacle

障碍
Meaning
something that blocks or makes progress difficult; a barrier
Example
Bad weather was the main obstacle to our journey.
坏天气是我们旅行的主要障碍。
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 verb /ˌaʊtˈstrɛtʃ/

outstretch

伸展
Meaning
To extend or stretch something outward.
Example
He outstretched his hand to help her up.
他伸出手来帮助她站起来。
B2 adjective + noun ˈɒptɪməl ˈtempərətʃər

optimal temperature

最佳温度
Meaning
The best or most favorable temperature for a particular purpose
Example
Winter provides optimal temperature for farming.
冬天提供了农业的最佳温度。
B2 noun /əbˈzɜːvər/

observer

观察者
Meaning
a person who watches or notices something
Example
The observer took notes during the meeting.
观察者在会议期间做了笔记。
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 /ˌɒbstəˈtrɪʃən/

obstetrician

产科医生
Meaning
A doctor specializing in pregnancy, childbirth, and women's reproductive health.
Example
The obstetrician monitored the mother’s health throughout the pregnancy.
产科医生在整个怀孕过程中监测了母亲的健康。
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 /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。
A2 noun /ˈɒm.lət/

Omelet

煎蛋饼
Meaning
a dish made from beaten eggs cooked in a frying pan and often folded around a filling
Example
She made a cheese omelet for breakfast.
她做了一个奶酪煎蛋饼作为早餐。
C2 noun /əbˈstrʌkʃənɪst/

obstructionist

Meaning
a person who deliberately delays or prevents progress by being uncooperative or oppositional
Example
The obstructionist in the committee kept delaying the decision-making process.
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。
C1 noun /ˈɔːrθədɑːksi/

orthodoxy

正统
Meaning
traditional or generally accepted beliefs and practices
Example
The religious leader defended the orthodoxy of the faith.
宗教领袖捍卫了信仰的正统性。
C2 verb /ˈɑːbdʒərˌɡeɪt/

objurgate

严厉批评
Meaning
to scold or rebuke severely
Example
The teacher objurgated the student for being dishonest.
老师因为学生不诚实而严厉批评了他。
C2 noun /oʊf/

Oaf

笨拙、愚蠢或麻木的人
Meaning
a clumsy, stupid, or insensitive person
Example
Don't be such an oaf - handle the dishes carefully!
不要做那种笨蛋 – 小心洗碗！
B2 noun /ˈaʊt.saɪ.dər/

Out-sider

局外人
Meaning
a person who does not belong to a particular group; someone not accepted by a group
Example
As an outsider, he found it difficult to understand their traditions.
作为外人，他发现很难理解他们的传统。
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。
A2 noun /ˈɒf.ɪs/

office

办公室
Meaning
a room or building where people work, usually at desks
Example
She left the office early to attend a family event.
她提前离开办公室去参加家庭活动。
C2 noun /ɒmˈnɪpətəns/

omnipotence

全能
Meaning
The quality of having unlimited power or authority.
Example
Many religions describe God’s omnipotence as absolute.
许多宗教将上帝的全能描述为绝对的。
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。
C1 noun /oʊˈeɪ.sɪs/

Oasis

绿洲
Meaning
a fertile spot in a desert where water is found; a pleasant refuge
Example
The travelers found an oasis after days in the desert.
旅行者在沙漠中几天后找到了一个绿洲。
B2 adjective /ˈɔː.də.li/

Orderly

有序的; 系统的; 平静的
Meaning
well-organized; systematic; peaceful
Example
Please keep your desk orderly and clean.
请保持您的桌面整齐和干净。
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。
A1 adjective/adverb /ˈoʊnli/

only

唯一
Meaning
without others; solely
Example
He is the only person who knows the secret.
他是唯一知道这个秘密的人。
C1 noun /əbˈzɜːvəns/

observance

遵守
Meaning
The practice of following a custom, rule, or religious law.
Example
The festival is held in observance of a centuries-old tradition.
该节庆是为了遵守一项百年传统而举行的。
B2 noun /əbˈsɛʃən/

obsession

痴迷
Meaning
An idea, thought, or concern that continually preoccupies or intrudes on a person's mind.
Example
His obsession with success drove him to work day and night.
他对成功的痴迷促使他日夜工作。
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 noun /əbˈstrʌkʃən/

obstruction

障碍
Meaning
Something that blocks or gets in the way; the action of obstructing.
Example
There was an obstruction on the railway track.
铁路上有一个障碍。
C1 noun ˌoʊ.vɚˈɡreɪ.zɪŋ

overgrazing

过度放牧
Meaning
The practice of allowing livestock to graze to the point of damaging vegetation.
Example
Overgrazing leads to soil erosion and loss of biodiversity.
过度放牧导致土壤侵蚀和生物多样性的丧失。
C1 noun /ˈɑd.ɪ.ti/

Oddity

奇异现象
Meaning
something that is strange or unusual; a peculiar trait
Example
His habit of sleeping standing up was considered an oddity.
他站着睡觉的习惯被视为一种奇异现象。
B2 verb /ˌoʊvərˈwɛlm/

overwhelm

Meaning
to overpower someone emotionally or physically; to be too much to handle
Example
She was overwhelmed with gratitude after receiving the help.
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。
B1 noun /ˈɑː.lɪv/

Olive

橄榄
Meaning
a small oval fruit with a hard pit, typically green or black, used for eating or making oil
Example
Olive oil is considered one of the healthiest cooking oils available.
橄榄油被认为是最健康的烹饪油之一。
B2 noun /ˌɔː.ri.enˈteɪ.ʃən/

orientation

定向
Meaning
the process of becoming familiar with a new situation or environment
Example
The company provides an orientation for all new employees.
公司为所有新员工提供定向培训。
A2 preposition /ˈɒntu/

onto

在…上
Meaning
moving to a position on the surface of something
Example
She jumped onto the table to get the book.
她跳到桌子上去拿书。
C1 verb /aʊst/

oust

驱逐
Meaning
To remove someone from a position or place of power or authority.
Example
The rebels ousted the dictator from power.
叛乱者将独裁者赶下台。
A2 verb /ˈɔːfər/

offer

提供
Meaning
to present something for acceptance or rejection; to propose
Example
She offered to help with the project.
她提出帮助这个项目。
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。
A1 adjective /oʊld/

old

旧的
Meaning
having lived for a long time; not new or young
Example
He still drives his old car.
他仍然开着他的旧车。
C2 noun /ˈɔɪl.mən/

Oilman

石油商
Meaning
a person who works in the oil industry; someone who sells oil or petroleum products
Example
The oilman discovered a new oil field in the desert.
石油商在沙漠中发现了一个新的油田。
B1 verb /ˈɒpəreɪtɪŋ/

operating

操作
Meaning
to control or manage the functioning of something
Example
The company has been operating in this market for five years.
公司已经在这个市场运营了五年。
C2 noun /ˈɔːrdnəns/

ordnance

军火
Meaning
Military supplies including weapons, ammunition, and combat equipment.
Example
The army stored ordnance in a secure facility outside the city.
军队在城市外的一个安全设施中存储军火。
B1 adjective /ˌoʊld ˈfæʃənd/

old-fashioned

过时的
Meaning
not modern; belonging to an earlier time
Example
He still wears an old-fashioned hat.
他仍然戴着一顶过时的帽子。
A2 noun /ˈʌn.jən/

Onion

洋葱
Meaning
a round vegetable with a strong taste and smell, made up of many layers
Example
I need to chop some onions for the curry recipe.
我需要切一些洋葱来做咖喱菜谱。
A2 noun /ˈɒbdʒɪkt/

object

物体
Meaning
a thing that can be seen and touched
Example
The table is an object in the room.
桌子是房间里的一个物体。
C1 adjective /ˌoʊvərˈrɔt/

overwrought

焦虑 / 过度紧张
Meaning
extremely agitated or nervous; excessively elaborate
Example
She was too overwrought to speak clearly after the accident.
她在事故后太焦虑，无法清楚地讲话。
C2 verb /ˈɑːskjʊleɪt/

osculate

亲吻
Meaning
To kiss.
Example
They osculated under the mistletoe during the party.
他们在派对上在槲寄生下接吻。
C1 noun ˌɒk.sɪˈdeɪ.ʃən

oxidation

氧化
Meaning
A chemical reaction that involves the combination of a substance with oxygen, often causing deterioration.
Example
Oxidation causes metal surfaces to weaken.
氧化会削弱金属表面。
A2 noun /əˈlɪmpɪks/

olympics

奥林匹克运动会
Meaning
an international sports competition held every four years with athletes from many countries
Example
The Olympics bring athletes from all over the world together.
奥林匹克运动会将全世界的运动员聚集在一起。
C1 verb /əbˈstrʌkt/

obstruct

阻碍
Meaning
to block or hinder progress; to prevent or impede movement
Example
The fallen tree obstructed the road for several hours.
倒下的树挡住了路几个小时。
B2 adverb /ˌoʊvərˈnaɪt/

Overnight

一夜之间; 突然; 非常快速
Meaning
during the night; suddenly; very quickly
Example
The city was transformed overnight.
这座城市一夜之间发生了变化。
B2 noun /ˌoʊ.vɚˈkraʊ.dɪŋ/

overcrowding

过度拥挤
Meaning
Excessive crowd or packed condition, having more people or vehicles in a place than the approved capacity.
Example
The subway system suffers from severe overcrowding during peak hours.
地铁系统在高峰时段面临严重的过度拥挤。
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。
C2 noun /ˈɒrɪz(ə)n/

orison

祷告
Meaning
a prayer, especially a devout or formal one
Example
He whispered a quiet orison before going to sleep.
他在睡觉前低声祈祷。
C1 noun /ˈaʊtˌɡroʊθ/

outgrowth

衍生物
Meaning
something that grows out of something else; a natural development or result
Example
The new policy was an outgrowth of years of debate.
新政策是多年辩论的衍生物。
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。
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 adjective /ˈɑːsɪˌfaɪd/

ossified

变成骨头，僵硬
Meaning
Turned into bone or become rigid; unwilling to change.
Example
The company had an ossified management structure that resisted innovation.
该公司有一个僵化的管理结构，抵制创新。
B1 verb /əbˈzɜːrv/

observe

观察
Meaning
to watch carefully; to notice or perceive something
Example
Scientists observe the behavior of animals in the wild.
科学家观察野生动物的行为。
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。
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 noun /ɒpˈtɪʃən/

optician

眼镜师
Meaning
A person who makes or sells glasses and contact lenses.
Example
The optician adjusted my new glasses to fit better.
眼镜师调整了我的新眼镜，以便更好地适应。
A1 preposition /ʌv/

of

的
Meaning
expressing the relationship between a part and a whole
Example
The book is on the table, in front of the window.
书在桌子上，在窗户前。
C2 noun /ˈɒlɪv bɑːb/

Olive barb

橄榄鲃
Meaning
A small freshwater fish with olive-colored body and barbels
Example
The olive barb is commonly found in South Asian rivers.
橄榄鲃常见于南亚的河流中。
C1 adjective /ˈɒptɪməm/

optimum

最优
Meaning
Most conducive to a favorable outcome; best.
Example
To achieve optimum results, we need to improve efficiency.
为了获得最佳结果，我们需要提高效率。
B2 adjective, verb /əbˈskjʊr/

obscure

模糊
Meaning
Not clearly expressed or understood; to make something difficult to see or understand.
Example
The meaning of the poem was obscure to most readers.
诗的意义对大多数读者来说是模糊的。
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。
B2 verb /ˌoʊvərˈloʊd/

overload

过载
Meaning
to load with too much weight or cargo; to give too much work or information
Example
Don't overload the washing machine or it might break down.
不要过载洗衣机，否则它可能会坏掉。
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。
C2 verb /ˈɑːblɪˌɡeɪt/

obligate

强迫
Meaning
to bind legally or morally; to compel someone to do something
Example
The contract obligates the company to provide timely service.
合同使公司有义务提供及时服务。
C2 noun /ˈoʊvərlɔːrd/

overlord

领主
Meaning
A ruler, master, or person of great power and authority over others.
Example
The peasants were forced to pay taxes to their overlord.
农民被迫向他们的领主交税。
C1 noun /ˈɔːr.ə.tɔːr.i/

oratory

演讲艺术
Meaning
The art of public speaking; skilled and confident delivery of speeches to an audience.
Example
His exceptional oratory skills won him the debate competition.
他出色的演讲技巧使他赢得了辩论比赛。
B2 adjective /əˈpəʊzd/

opposed

反对的
Meaning
being against or in disagreement with something
Example
She is strongly opposed to animal testing.
她坚决反对动物实验。
B1 noun /ˈɑp.ʃən/

Option

选项
Meaning
a thing that is or may be chosen; an alternative course of action
Example
You have the option to work from home or office.
你可以选择在家工作或在办公室工作。
B2 verb /ˌoʊvərˈtɜrn/

overturn

推翻 / 取消裁决
Meaning
to turn something upside down or to reverse a decision or judgment
Example
The court decided to overturn the previous ruling.
法院决定推翻先前的裁决。
C1 noun /ˈɒptɪks/

optics

光学
Meaning
The branch of physics dealing with light and vision.
Example
She studied optics to understand how lenses work.
她学习了光学，以了解镜头是如何工作的。
C2 adjective /ˈəʊ.dər.əs/

Odorous

芬芳的; 香气的
Meaning
having a strong smell; fragrant; aromatic
Example
The garden was filled with odorous flowers.
花园里充满了芬芳的花朵。
C2 noun /ɒkˈteɪvoʊ/

octavo

八开 (通过将纸张折叠成八个部分而产生的书籍大小)
Meaning
A size of book page resulting from folding a sheet of paper into eight leaves (sixteen pages).
Example
The old library contained rare octavo editions of Shakespeare.
这座古老的图书馆里有莎士比亚的稀有八开版书籍。
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。
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 ˈoʊzoʊn dɪˈpliʃən

ozone depletion

臭氧消耗
Meaning
The reduction in the amount of ozone in the Earth's stratosphere, leading to increased UV radiation.
Example
Ozone depletion increases UV radiation.
臭氧消耗增加了紫外线辐射。
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。
C2 adjective /əbˈstrɛpərəs/

obstreperous

喧闹且难以控制
Meaning
Noisy and difficult to control.
Example
The obstreperous students disrupted the class.
那些喧闹的学生打乱了课堂。
C1 adjective /ˈɒptɪkəl/

optical

光学的
Meaning
related to or used in seeing or sight
Example
The optical illusion fooled everyone at the exhibition.
光学幻觉在展览会上迷惑了所有人。
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.
B1 verb /ˈɔːrɡənaɪz/

organize

组织
Meaning
to arrange systematically; to plan and coordinate
Example
She organized a surprise party for her friend.
她为她的朋友组织了一个惊喜派对。
A1 noun/adjective/adverb /ˌaʊtˈsaɪd/

outside

外面
Meaning
the external part or surface of something; beyond the boundary
Example
Children were playing outside in the yard.
孩子们在院子外面玩。
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。
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。
A2 adjective /əˈlɪmpɪk/

olympic

奥林匹克
Meaning
related to the Olympic Games, a major international sporting event
Example
She trained hard to compete in the Olympic Games.
她努力训练，为了参加奥林匹克运动会。
B2 noun /ˈɔr.fən/

Orphan

孤儿
Meaning
a child whose parents are dead; someone without protective support
Example
The orphan was adopted by a loving family.
孤儿被一户充满爱心的家庭收养了。
C2 noun /ˈɒksɪdənt/

occident

西方
Meaning
The countries of the West, especially Europe and America.
Example
The Occident has a long history of philosophical thought.
西方有着悠久的哲学思想历史。
C1 noun /oʊˈbɪt.ʃu.er.i/

Obituary

讣告
Meaning
a notice of someone's death published in a newspaper; biographical account of deceased person
Example
The newspaper published his obituary yesterday.
报纸昨天发布了他的讣告。
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 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。
B2 adjective /ˈɔː.rəl/

Oral

口头的；与嘴巴相关的
Meaning
spoken rather than written; relating to the mouth
Example
The oral examination will test your speaking skills.
口头考试将测试你的口语技能。
C2 noun /ɑːlˈfækʃən/

olfaction

嗅觉
Meaning
The sense of smell; the process of detecting and perceiving odors.
Example
Dogs have a highly developed sense of olfaction.
狗的嗅觉非常发达。
C1 adjective /əˈblaɪdʒɪŋ/

obliging

乐于助人
Meaning
Willing to help or do favors; accommodating.
Example
The staff at the hotel were very obliging and friendly.
酒店的工作人员非常乐于助人且友好。
A1 conjunction /ɔːr/

or

或
Meaning
used to link alternatives
Example
You can have tea or coffee.
你可以喝茶或咖啡。
B1 adjective /əˈbiː.di.ənt/

Obedient

顺从的
Meaning
willing to comply with orders or instructions; submissive
Example
The obedient student always follows the teacher's instructions.
听话的学生总是遵循老师的指示。
C2 verb /ˈɒsɪfaɪ/

ossify

骨化
Meaning
to turn into bone or become rigid and inflexible
Example
With age, some tissues tend to ossify.
随着年龄的增长，一些组织会变得僵硬。