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B2 verb /əbˈteɪn/

obtain

取得する
Meaning
to get or acquire something
Example
You need to obtain a visa before traveling abroad.
あなたは海外に行く前にビザを取得する必要があります。
B2 noun /ˈɔːrɡənaɪzər/

organizer

主催者
Meaning
a person who arranges or coordinates activities, events, or groups; a tool or item used to keep things in order
Example
She worked as the main organizer of the international conference.
彼女は国際会議の主要な主催者だった。
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.
海洋は地球の表面の70%以上を覆っています。
C2 noun /ˈɒn.rʌʃ/

onrush

突発的な流れ
Meaning
A sudden powerful forward or downward rush or flow.
Example
The onrush of water swept away the bridge.
水の突発的な流れが橋を流しました。
C2 adjective /ˈɑːsɪˌfaɪd/

ossified

骨に変わった、硬直した
Meaning
Turned into bone or become rigid; unwilling to change.
Example
The company had an ossified management structure that resisted innovation.
その会社は、革新に抵抗する硬直した管理構造を持っていました。
C1 adjective /aʊtˈmoʊdɪd/

outmoded

時代遅れ
Meaning
No longer in fashion or useful; outdated.
Example
That old computer is completely outmoded.
その古いコンピューターは完全に時代遅れです。
C1 adjective /ˌoʊvərˈbɛrɪŋ/

overbearing

押しつけがましい
Meaning
unpleasantly or arrogantly domineering
Example
His overbearing attitude made everyone uncomfortable.
彼の押しつけがましい態度は、みんなを不快にさせた。
B2 adverb /əˈfɪʃəli/

officially

公式に
Meaning
in a formal or authorized way
Example
The building was officially opened by the mayor.
その建物は市長によって公式に開かれました。
A1 noun/adjective/adverb /ˌaʊtˈsaɪd/

outside

Meaning
the external part or surface of something; beyond the boundary
Example
Children were playing outside in the yard.
子供たちは庭で外で遊んでいました。
C2 noun /əbˈstɛtrɪks/

obstetrics

産科
Meaning
The branch of medicine dealing with childbirth and care of women giving birth.
Example
She is studying obstetrics to become a specialist in childbirth.
彼女は産科を学んで、出産専門医になろうとしている。
B2 noun /ˈaʊtbɜːrst/

outburst

感情または活動の突然の爆発
Meaning
a sudden release of strong emotion or activity
Example
She had an angry outburst during the meeting.
会議中に彼女は怒りの爆発をした。
C1 noun /oʊˈbɪt.ʃu.er.i/

Obituary

訃報
Meaning
a notice of someone's death published in a newspaper; biographical account of deceased person
Example
The newspaper published his obituary yesterday.
新聞は昨日彼の訃報を掲載しました。
A1 preposition /ʌv/

of

Meaning
expressing the relationship between a part and a whole
Example
The book is on the table, in front of the window.
本はテーブルの上にあり、窓の前にあります。
B2 noun /ˈɒpəreɪtər/

operator

オペレーター
Meaning
a person who operates equipment, a business, or controls something
Example
The machine operator ensured that everything ran smoothly.
機械オペレーターは、すべてがスムーズに動作することを確認しました。
B2 adjective /ˈɔɪl.i/

Oily

油っぽい; 油で覆われた; 脂っこい
Meaning
covered with oil; containing oil; greasy
Example
Her oily skin needs special care.
彼女の油っぽい肌は特別なケアが必要です。
B2 noun /oʊk/

oak

オークの木
Meaning
a large tree that produces acorns and has strong, hard wood
Example
The old oak tree provided shade for the entire yard.
古いオークの木は庭全体に日陰を提供しました。
A2 noun /əˈlɪmpɪks/

olympics

オリンピック競技大会
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.
オリンピックは世界中のアスリートを一堂に集めます。
B1 verb /oʊ/

owe

借りがある
Meaning
to be under obligation to pay or repay; to be indebted
Example
I owe my success to my parents' support.
私は両親の支援のおかげで成功しました。
C2 noun /ˌɔːrəˈtɔːri.oʊ/

oratorio

宗教音楽作品
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.
ヘンデルの『メサイア』は最も有名なオラトリオの1つです。
A2 noun /ˈɒpərə/

opera

オペラ
Meaning
a dramatic performance in which the actors sing most of their lines
Example
We watched a beautiful opera at the theater last night.
昨晩、劇場で美しいオペラを観ました。
B1 verb অকার্স

occurs

起こる
Meaning
Happens or takes place, especially as a result of something.
Example
Snowfall occurs in regions with freezing temperatures.
雪は氷点下の温度を持つ地域で起こります。
C2 adjective /əˈprəʊ.bri.əs/

opprobrious

侮辱的な
Meaning
Expressing strong criticism or scorn.
Example
He made opprobrious remarks about his opponent.
彼は対戦相手に対して侮辱的な発言をしました。
C2 noun ˌɒbfəsˈkeɪʃən

obfuscation

難解化, 混乱
Meaning
The action of making something obscure, unclear, or unintelligible.
Example
The obfuscation of the data made it difficult to interpret.
データの難解化により、解釈が困難になりました。
C2 verb /ˌaʊtməˈnuːvər/

outmaneuver

巧妙に出し抜く
Meaning
to gain an advantage over an opponent by skillful or clever action
Example
The smaller company managed to outmaneuver its larger rival.
小さな会社は大きな競争相手を巧妙に出し抜くことに成功した。
A1 adverb /aʊt/

out

Meaning
moving or appearing away from the inside or center; not at home or present
Example
He stepped out of the room quietly.
彼は静かに部屋を出ました。
A1 adverb /ɔːf/

off

オフ
Meaning
away from a place, position, or time; not functioning
Example
He turned off the light before leaving the room.
彼は部屋を出る前に電気をオフにしました。
C1 adjective /ˈɒptɪməm/

optimum

最適
Meaning
Most conducive to a favorable outcome; best.
Example
To achieve optimum results, we need to improve efficiency.
最適な結果を得るためには、効率を改善する必要があります。
C1 noun /ˈɒn.slɔːt/

onslaught

猛攻
Meaning
A fierce or destructive attack.
Example
The village faced an onslaught of enemy forces.
その村は敵軍の猛攻に直面しました。
B2 verb /ˌoʊvərˈiːt/

overeat

幸福
Meaning
To eat more food than the body needs.
Example
She tends to overeat when she is stressed.
彼女は賞を受け取ったとき、喜びを隠すことができませんでした。
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.
多くの宗教では、神は全能だと考えられています。
A1 noun /ɒkˈtoʊbər/

october

10月
Meaning
the tenth month of the year in the Gregorian calendar
Example
The weather becomes cooler in October.
10月になると天気が涼しくなります。
C1 noun /ˈɑd.ɪ.ti/

Oddity

珍奇な現象
Meaning
something that is strange or unusual; a peculiar trait
Example
His habit of sleeping standing up was considered an oddity.
彼の立って寝る習慣は珍奇な現象と見なされていました。
C1 verb /ˈɔːstrəˌsaɪz/

ostracize

追放する
Meaning
to exclude someone from a group or society; to banish or shun
Example
After the scandal, he was ostracized by his former colleagues.
スキャンダル後、彼は元同僚に追放された。
A2 preposition /ˈɒntu/

onto

上に
Meaning
moving to a position on the surface of something
Example
She jumped onto the table to get the book.
彼女は本を取るためにテーブルの上に飛び乗った。
C2 verb /ˈɒsɪfaɪ/

ossify

骨化する
Meaning
to turn into bone or become rigid and inflexible
Example
With age, some tissues tend to ossify.
年を重ねると、一部の組織が骨化する傾向があります。
C2 adjective /ɑːlˈfæktəri/

olfactory

Meaning
Relating to the sense of smell.
Example
The perfume activated her olfactory nerves immediately.
C1 noun /ˈɒktəɡən/

octagon

八角形
Meaning
A polygon with eight sides and eight angles.
Example
The stop sign is shaped like an octagon.
ストップサインは八角形をしています。
C1 adjective /ˌɒmnɪˈprezənt/

omnipresent

至る所に存在する
Meaning
(of God) present everywhere at the same time.
Example
Social media has become an omnipresent force in modern society.
ソーシャルメディアは現代社会において至る所に存在する力となりました。
A2 adjective/adverb /ˈɒnˌlaɪn/

online

オンライン
Meaning
connected to or available through the internet
Example
I prefer shopping online rather than going to stores.
私はお店に行くよりもオンラインで買い物をする方が好きです。
B2 noun /ˈɔr.fən.ɪʒ/

Orphanage

孤児院
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.
チャリティーはホームレスの子供たちのために新しい孤児院を建てました。
C1 verb /ˌaʊtˈstrɪp/

outstrip

凌駕する
Meaning
To go faster or do better than someone or something; to surpass.
Example
The company outstripped its competitors in sales last year.
その会社は昨年、販売で競合他社を上回った。
C1 noun /ˌoʊvərprəˈdʌkʃən/

overproduction

過剰生産
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.
経済危機は商品の過剰生産によって引き起こされた。
C2 adjective /ˈɒf.biːt/

offbeat

風変わり
Meaning
Unusual, unconventional, or different from the norm.
Example
She has a very offbeat sense of humor.
彼女はとても風変わりなユーモアを持っています。
B1 verb /ˈɒpəreɪtɪŋ/

operating

運営する
Meaning
to control or manage the functioning of something
Example
The company has been operating in this market for five years.
その会社はこの市場で5年間運営されています。
A2 noun /ɔɪl/

Oil

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.
野菜を加える前にフライパンで油を温めます。
B2 adjective /ˈɒp.tɪ.məl/

optimal

最適、最良
Meaning
Best or most favorable; the most effective under particular conditions.
Example
The optimal temperature for plant growth is around 25°C.
植物の成長に最適な温度は約25°Cです。
A1 adjective /ˈʌðər/

other

他の
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.
これを欲しくない、他のを取るつもりだ。
B1 verb /əbˈzɜːrv/

observe

観察する
Meaning
to watch carefully; to notice or perceive something
Example
Scientists observe the behavior of animals in the wild.
科学者たちは野生動物の行動を観察します。
C1 adjective /ˌɔːrnəˈmɛntl/

ornamental

装飾的な
Meaning
Serving as decoration; decorative rather than functional.
Example
The garden was filled with ornamental plants.
庭は装飾的な植物でいっぱいだった。
C2 adjective /əbˈstrɛpərəs/

obstreperous

騒がしくて制御が難しい
Meaning
Noisy and difficult to control.
Example
The obstreperous students disrupted the class.
騒がしい学生たちが授業を妨害した。
C1 noun /ˌɑːsɪˈleɪʃən/

oscillation

振動
Meaning
The movement back and forth at a regular speed.
Example
The oscillation of the pendulum controls the clock.
振り子の振動が時計を制御します。
C1 adjective /ˈɒptɪk/

optic

視覚の
Meaning
Relating to the eye or vision.
Example
The optic nerve carries signals from the eye to the brain.
視神経は目から脳に信号を伝達します。
B2 noun /ˈoʊtˌmiːl/

oatmeal

オートミール
Meaning
A type of porridge made from ground oats, often eaten for breakfast.
Example
She eats a bowl of oatmeal every morning for breakfast.
彼女は毎朝、朝食にオートミールを一杯食べます。
B2 verb /ˌoʊvərˈduː/

overdo

やりすぎる
Meaning
to do something too much; to exaggerate or carry to excess
Example
Don't overdo the exercise on your first day at the gym.
初日はジムで運動をやりすぎないでください。
B2 noun /əbˈsɛʃən/

obsession

執着
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.
成功への執着が彼を昼夜働かせた。
C1 adjective /əˈprɛs.ɪv/

Oppressive

抑圧的
Meaning
Harsh and authoritarian; overwhelming; causing distress; tyrannical;
Example
The oppressive heat made it difficult to work outside during the summer.
厳しい暑さは夏の間外で働くのを難しくした。
B2 verb /əˈrɪdʒɪneɪt/

originate

起源する
Meaning
to come into existence; to begin; to create or produce
Example
The tradition originated in ancient times.
その伝統は古代の時代に起源を持っています。
B2 adjective /ˈɔː.rəl/

Oral

口頭の; 口に関する
Meaning
spoken rather than written; relating to the mouth
Example
The oral examination will test your speaking skills.
口頭試験はあなたの話す能力をテストします。
C1 noun /ɒpˈtɒmətri/

optometry

視力検査学
Meaning
The practice or profession of examining the eyes and prescribing corrective lenses.
Example
She studied optometry at the university to become an eye specialist.
彼女は大学でオプトメトリーを学び、眼科専門医になりました。
B2 noun /ˈɒkjʊpənt/

occupant

乗客
Meaning
A person who resides in or is present in a house, vehicle, seat, or place.
Example
The car had three occupants at the time of the accident.
事故の時、車には三人の乗客がいました。
C2 adjective /ˈɔːrəˌtʌnd/

orotund

豊かで明確な声
Meaning
full, rich, and clear in sound; pompous in style
Example
The actor's orotund voice filled the theater.
俳優の豊かな声が劇場に響き渡った。
C2 noun /oʊˈbleɪʃən/

oblation

奉納
Meaning
a religious offering, especially of bread or wine to God
Example
The priest placed the oblation on the altar during the ceremony.
司祭は儀式の間に祭壇に奉納を置きました。
B2 noun /ˈoʊ.dər/

Odour

臭い
Meaning
a distinctive smell, especially an unpleasant one
Example
The odour of fresh bread filled the kitchen.
新鮮なパンの臭いがキッチンに広がった。
C2 noun /ˈɒbsɪkwiːz/

obsequies

葬儀儀式
Meaning
Funeral rites or ceremonies.
Example
The obsequies for the late leader drew thousands of mourners.
故リーダーの葬儀儀式には、数千人の弔問客が集まりました。
C1 verb /ɔːrˈdeɪn/

ordain

Meaning
To officially make someone a priest or minister; to decree or order something officially.
Example
The bishop will ordain three new priests this Sunday.
C2 noun /əbˈsɪdiən/

obsidian

オブシディアン (黒いガラスのような火山岩)
Meaning
A hard, dark, glasslike volcanic rock formed by rapid solidification of lava.
Example
The knife was made from sharp obsidian.
ナイフは鋭いオブシディアンで作られていた。
B2 verb /ˌoʊvərˈlʊk/

overlook

見落とす
Meaning
to fail to notice or consider something; to have a view from above
Example
It's easy to overlook small details when you're in a hurry.
急いでいると、細かい点を見落とすことがあります。
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.
彼女はレンズがどのように機能するかを理解するために光学を学びました。
B2 verb /ˌoʊvərˈteɪk/

overtake

追い越す
Meaning
to catch up with and pass someone or something; to surpass
Example
The runner managed to overtake his competitor in the final lap.
ランナーは最後の周回で競争相手を追い越しました。
C1 noun /ˈɔɪntmənt/

ointment

軟膏
Meaning
A smooth, oily substance applied to the skin for healing or soothing.
Example
The doctor prescribed an ointment for the burn on his arm.
医師は彼の腕のやけどのために軟膏を処方しました。
C1 noun /ˈəʊ.nəs/

onus

責任
Meaning
A duty or responsibility, especially a heavy one.
Example
The onus is on the government to provide relief to the victims.
犠牲者に支援を提供する責任は政府にあります。
C1 noun ˌoʊ.vɚˈɡreɪ.zɪŋ

overgrazing

過剰放牧
Meaning
The practice of allowing livestock to graze to the point of damaging vegetation.
Example
Overgrazing leads to soil erosion and loss of biodiversity.
過剰放牧は土壌の浸食と生物多様性の喪失を引き起こします。
B2 noun /ˈaʊt.saɪ.dər/

Out-sider

アウトサイダー
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.
アウトサイダーとして、彼は彼らの伝統を理解するのが難しいと感じました。
A1 adjective /əʊˈkeɪ/

okay

大丈夫
Meaning
used to express agreement or acceptance
Example
It's okay to leave early today.
今日は早く帰るのは大丈夫です。
C2 verb /ˌoʊvərˈliːp/

overleap

飛び越える
Meaning
To jump over something; to omit or disregard something.
Example
He managed to overleap the fence easily.
彼は簡単にフェンスを飛び越えました。
C2 noun /ˈɑb.lə.kwi/

Obloquy

厳しい批判または言葉による虐待; 公共の非難
Meaning
harsh criticism or verbal abuse; strong public condemnation
Example
The politician faced obloquy after the scandal.
政治家はスキャンダルの後、厳しい批判を受けました。
B2 noun /ˈoʊvərpæs/

overpass

高架橋
Meaning
A bridge that carries one road or railway over another.
Example
The new overpass reduced traffic congestion in the city.
新しい高架橋は市内の交通渋滞を減らしました。
C1 verb /ˌoʊvərˈθroʊ/

overthrow

幸せ
Meaning
To remove a leader or government from power, often by force.
Example
The rebels planned to overthrow the corrupt regime.
彼女は賞を受け取ったとき、幸せを隠すことができなかった。
C1 adjective /ˌɔː.riˈen.təl/

Oriental

東アジアの国々に関連する; 東方
Meaning
relating to the countries of East Asia; eastern
Example
The museum has a beautiful collection of oriental art.
博物館には美しいオリエンタルアートのコレクションがあります。
C2 verb /ˌoʊvərˈstraɪd/

overstride

大きな一歩で越える
Meaning
To stride over something; to step across with long steps.
Example
He managed to overstride the narrow stream with ease.
彼は狭い小川を簡単に越えることができました。
B2 noun /ˈɔːɡənɪzəm/

organism

生物
Meaning
a living thing that has an organized structure and can grow and reproduce
Example
Every organism needs water to survive.
すべての生物は生き残るために水を必要とします。
B2 noun /əˌrɪʒ.əˈnæl.ə.ti/

Originality

独創性
Meaning
the quality of being novel or unusual; the ability to think independently and creatively
Example
The artist's work showed great originality and creativity.
アーティストの作品は大きな独創性と創造性を示した。
B1 noun /ˈɑp.ʃən/

Option

オプション
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.
自宅またはオフィスから仕事をするオプションがあります。
B1 adverb /ˈʌðərwaɪz/

Otherwise

さもないと; 他の方法で
Meaning
in a different way; if not; or else; apart from that
Example
Study hard, otherwise you will fail the exam.
一生懸命勉強しなさい、さもないと試験に落ちます。
C1 verb /ˌaʊtˈduː/

outdo

超える
Meaning
To do better than someone else; to surpass.
Example
She always tries to outdo her classmates in exams.
彼女は試験でクラスメートを常に超えようとします。
C1 noun /ˈɔːrdɪnəns/

ordinance

条例
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.
市議会は公共公園での喫煙を禁じる条例を可決しました。
C2 noun /ɔːˈreɪʃən/

oration

演説
Meaning
A formal speech, especially one given on a ceremonial occasion
Example
The president delivered an inspiring oration.
大統領は感動的な演説を行いました。
C2 noun /ɒmˈnɪʃəns/

omniscience

全知
Meaning
the state of knowing everything
Example
The novel's narrator has an air of omniscience, revealing every character's thoughts.
小説の語り手は全知の空気をまとい、すべてのキャラクターの考えを明らかにしている。
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.
その祭りは、数世代にわたる伝統を遵守して行われます。
C2 adjective /ˌoʊpəˈlɛsənt/

opalescent

オパール色の
Meaning
showing or reflecting a milky, iridescent light like an opal
Example
The opalescent sky glowed with shades of pink and blue.
オパレッセントな空はピンクと青の色合いで輝いていた。
C1 noun /ˌɑːk.sɪˈmɔːr.ɒn/

oxymoron

オキシモロン
Meaning
a figure of speech where two contradictory terms are combined
Example
The phrase 'deafening silence' is a classic oxymoron.
「耳をつんざくような静けさ」というフレーズは、典型的なオキシモロンです。
C1 noun /ˈɒfʃuːt/

offshoot

分岐
Meaning
A branch or result that develops from something larger or more important.
Example
The startup was an offshoot of a major tech company.
そのスタートアップは大手テクノロジー企業からの分岐でした。
C1 adjective əʊˈpeɪk

opaque

不透明, 理解しにくい
Meaning
Not able to be seen through; not transparent; difficult to understand.
Example
The glass was too opaque to see through.
そのガラスは不透明すぎて、透けて見えませんでした。
C1 noun /ˈɔːr.ə.tɔːr.i/

oratory

弁論術
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.
彼の卓越した弁論術は、ディベートコンペティションで彼に勝利をもたらしました。
C2 adjective /ˌɔːfˈkiː/

off-key

外れた音
Meaning
out of tune; not in accordance with expected standards
Example
The singer was slightly off-key during the performance.
歌手はパフォーマンス中に少し外れた音だった。
C1 adjective /əˈbliːk/

Oblique

斜め; 対角線; 間接的または回避的
Meaning
slanting; diagonal; indirect or evasive
Example
The artist drew an oblique line across the canvas.
アーティストはキャンバスに斜めの線を描いた。
A2 noun /ˈɒf.ɪs/

office

オフィス
Meaning
a room or building where people work, usually at desks
Example
She left the office early to attend a family event.
彼女は家族のイベントに出席するために早くオフィスを出ました。
C1 adjective ˈɒk.sɪ.də.tɪv

oxidative

酸化に関連する
Meaning
Related to or caused by oxidation, especially cellular damage from free radicals.
Example
Excess stress can lead to oxidative damage in cells.
過度のストレスは細胞に酸化的な損傷を引き起こす可能性があります。
C1 verb /ˌoʊvərˈrʌn/

overrun

侵略する
Meaning
to spread over or occupy completely; to exceed a limit or time
Example
The garden was overrun with weeds.
庭は雑草に覆われていた。
B2 noun ˈaʊt.pʊt

output

生産量
Meaning
The amount of something produced by a person, machine, or industry.
Example
Climate change reduces agricultural output.
気候変動は農業の生産量を減少させます。
C1 noun /oʊˈveɪʃən/

ovation

拍手
Meaning
an enthusiastic show of approval, especially by clapping hands
Example
The actor received a standing ovation after his performance.
俳優はパフォーマンス後にスタンディングオベーションを受けました。
B2 noun /ˈaʊtlet/

outlet

出口
Meaning
a means by which something is released, expressed, or distributed
Example
Art is a great outlet for emotions.
アートは感情のための素晴らしい出口です。
C2 adjective /əˈfɪʃəs/

officious

干渉的な
Meaning
Excessively eager to offer unwanted help or advice; meddlesome.
Example
The officious guard kept interrupting the visitors with unnecessary instructions.
その干渉的な警備員は訪問者に不必要な指示で何度も中断させた。
B1 verb /ˈɒpəreɪt/

operate

操作する
Meaning
to function; to control or manage; to perform surgery
Example
The surgeon will operate on the patient tomorrow.
外科医は明日患者を手術します。
B2 noun /ˈaʊt.breɪk/

Out-break

発生
Meaning
a sudden occurrence or eruption of something, especially disease or violence
Example
The outbreak of flu affected many students in the school.
インフルエンザの流行は学校の多くの生徒に影響を与えた。
B1 noun ˌɔː.ɡən.aɪˈzeɪ.ʃənz

organizations

組織
Meaning
Organized groups of people with a particular purpose
Example
Organizations play a key role in policymaking.
組織は政策形成において重要な役割を果たします。
C2 verb /əbˈtruːd/

obtrude

押し付ける
Meaning
to force oneself or one's ideas into a situation uninvited or inappropriately
Example
He didn’t want to obtrude into their private conversation.
彼は彼らのプライベートな会話に押し付けたくなかった。
C2 noun /oʊˈbeɪsəns/

obeisance

敬意
Meaning
A gesture of respect such as a bow or curtsy.
Example
They bowed in obeisance to the king.
彼らは王に対して敬意を示すためにお辞儀をした。
C2 noun /ˈɒkjʊlɪst/

oculist

眼科医
Meaning
An old-fashioned term for an eye doctor or ophthalmologist.
Example
The village oculist was known for treating various eye diseases.
村のオキュリストは、さまざまな目の病気を治療することで知られていました。
B2 adjective /aʊtˈstændɪŋ/

outstanding

優れた
Meaning
extremely good or impressive; not yet resolved or paid
Example
She received an award for her outstanding performance.
彼女は優れたパフォーマンスで賞を受賞しました。
C2 noun /ˈəʊpəs/

opus

創作作品
Meaning
A creative work, especially a large and important piece of music or art.
Example
The composer considered the symphony his greatest opus.
作曲家は交響曲を自分の最も偉大な創作作品と見なしていました。
C1 adjective /əbˈdʒek.ʃən.ə.bəl/

Objectionable

不快な
Meaning
arousing distaste or opposition; unpleasant or offensive
Example
His objectionable behavior made everyone uncomfortable.
彼の不快な行動は、皆を不快にさせた。
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.
C2 adjective /ˈɒfɪʃ/

offish

無愛想
Meaning
Unfriendly, distant, or reserved in manner.
Example
He seemed offish at the party and avoided most conversations.
彼はパーティーで無愛想に見え、大半の会話を避けていました。
A1 interjection /oʊ/

oh

オー
Meaning
used to express surprise, realization, or understanding
Example
Oh, I didn't know you were here!
オー、あなたがここにいるとは思わなかった!
C2 noun /ˌɒpəˈrɛtə/

operetta

軽いオペラ
Meaning
a short opera with light and humorous themes
Example
The theater staged a famous operetta by Gilbert and Sullivan.
劇場はギルバートとサリヴァンの有名な軽いオペラを上演しました。
C1 verb /aʊst/

oust

追放する
Meaning
To remove someone from a position or place of power or authority.
Example
The rebels ousted the dictator from power.
反乱者は独裁者を権力から追い出しました。
A2 noun /ˈoʊ.nər/

Owner

所有者
Meaning
a person who owns something; someone who has legal possession of property
Example
The owner of the restaurant greeted us warmly.
レストランの所有者は私たちを温かく迎え入れてくれました。
C2 noun /ˈɔːrdʒi/

orgy

乱行
Meaning
A wild party involving excessive indulgence, especially of a sexual nature.
Example
The novel described a scandalous orgy in a wealthy mansion.
その小説は、裕福な邸宅でのスキャンダラスな乱行を描いています。
B2 noun ˈoʊzoʊn dɪˈpliʃən

ozone depletion

オゾン層の減少
Meaning
The reduction in the amount of ozone in the Earth's stratosphere, leading to increased UV radiation.
Example
Ozone depletion increases UV radiation.
オゾン層の減少はUV放射線を増加させます。
C1 noun /ˈɒf.sprɪŋ/

offspring

子孫
Meaning
a person's child or children; an animal's young
Example
The bird carefully fed its offspring.
その鳥は注意深く自分の子孫に餌を与えました。