obstetrician
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C1 noun /ˌɒbstəˈtrɪʃən/

obstetrician

産科医
Meaning
A doctor specializing in pregnancy, childbirth, and women's reproductive health.
Example
The obstetrician monitored the mother’s health throughout the pregnancy.
産科医は妊娠中の母親の健康を監視しました。
C1 noun /ˈɔːrθədɑːksi/

orthodoxy

正統
Meaning
traditional or generally accepted beliefs and practices
Example
The religious leader defended the orthodoxy of the faith.
宗教指導者は信仰の正統性を守った。
A1 preposition, adverb /ˈoʊvər/

over

上に
Meaning
across, on top of, or beyond
Example
The book is lying over the table.
本はテーブルの上にあります。
C1 adjective/adverb /ˌɒfˈhænd/

offhand

軽率
Meaning
Without previous thought or preparation; casual and sometimes dismissive.
Example
She gave an offhand reply to his serious question.
彼女は彼の真剣な質問に対して、軽率な返答をした。
C1 noun /əˈpreʃ.ən/

Oppression

抑圧; 虐待; 圧政;
Meaning
cruel or unjust treatment or exercise of authority; the state of being subject to harsh treatment
Example
The people fought against political oppression.
人々は政治的な抑圧に反対して戦った。
B1 noun /ˈɑː.lɪv/

Olive

オリーブ
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.
オリーブオイルは、最も健康的な料理用オイルの一つと見なされています。
B1 verb /ˈɔːrɡənaɪz/

organize

整理する
Meaning
to arrange systematically; to plan and coordinate
Example
She organized a surprise party for her friend.
彼女は友達のためにサプライズパーティーを企画した。
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。
B1 adjective /əˈkeɪ.ʒən.əl/

Occasional

偶然の
Meaning
occurring infrequently or irregularly; happening from time to time
Example
She enjoys occasional walks in the park.
彼女は公園で偶然の散歩を楽しんでいます。
A1 verb /ˈoʊpən/

open

開ける
Meaning
to move something so as to allow access; to begin
Example
Please open the door for me.
ドアを開けてください。
B2 noun ˈəʊnəʃɪp

ownership

所有権
Meaning
The act, state, or right of possessing something; legal title to something.
Example
Ownership of resources was crucial.
資源の所有権は重要でした。
C1 noun /ˈaʊtˌɡroʊθ/

outgrowth

成長
Meaning
something that grows out of something else; a natural development or result
Example
The new policy was an outgrowth of years of debate.
新しい政策は数年の議論の成長でした。
B2 noun ɔːˈɡæn.ɪk fuːdz

organic foods

オーガニック食品
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.
オーガニック食品は加工食品よりも健康的です。
C1 noun /oʊˈeɪ.sɪs/

Oasis

オアシス
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.
旅行者たちは砂漠で数日後にオアシスを見つけました。
B2 adjective /ˌɔːɡənaɪˈzeɪʃənəl/

organizational

組織的
Meaning
relating to the structure or arrangement of a company or group
Example
He works on improving the organizational structure of the company.
彼は会社の組織構造を改善するために働いています。
C1 adjective /əbˈstrʌk.tɪv/

Obstructive

妨害的な
Meaning
deliberately creating difficulties or preventing progress; hindering or blocking something
Example
The obstructive policies hindered economic growth.
妨害的な政策は経済成長を阻害した。
C1 adjective /əbˈzɜːrvənt/

Observant

観察力のある
Meaning
quick to notice things; watchful; attentive
Example
The observant detective noticed every small detail at the crime scene.
観察力のある探偵は犯罪現場のあらゆる小さな詳細に気づきました。
A2 noun /ˈɒbdʒɪkt/

object

物体
Meaning
a thing that can be seen and touched
Example
The table is an object in the room.
テーブルは部屋の中の物体です。
C2 noun /ˌɒktədʒəˈnɛəriən/

octogenarian

80歳代の人
Meaning
A person who is between 80 and 89 years old.
Example
The octogenarian still jogs every morning to stay healthy.
そのオクトジェネリアンは毎朝健康を維持するためにジョギングをしています。
C1 adjective /ˌoʊvərˈbloʊn/

overblown

誇張された
Meaning
excessively exaggerated or inflated
Example
The controversy was overblown by the media.
メディアによって論争は誇張されました。
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。
C2 noun /ˈɔːrɪndʒfɪn ˈleɪbiːoʊ/

Orangefin labeo

オレンジフィンラベオ
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.
オレンジフィンラベオはバングラデシュで重要な食用魚です。
B1 noun /ˈɔːfɪsər/

officer

警官
Meaning
a person in a position of authority, especially in law enforcement
Example
The officer gave him a ticket for speeding.
警官はスピード違反で彼にチケットを渡した。
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。
B2 noun /əˈfɛns/

offense

犯罪
Meaning
an illegal act; a crime
Example
The offense was committed in broad daylight.
その罪は昼間に犯されました。
C1 adjective /ˈɑp.ər.ə.tɪv/

Operative

作動中の; 効力を持つ; 仕事をしている; 操作可能な;
Meaning
Functioning; in effect; working; active;
Example
The new safety protocols became operative immediately after the accident.
新しい安全プロトコルは事故後すぐに作動しました。
C1 verb /aʊtˈlæst/

outlast

他より長く続く
Meaning
to continue longer than; to endure beyond someone or something else
Example
The old castle has outlasted many generations.
その古い城は多くの世代を超えて生き残りました。
C1 adjective /ˌɔːrθəˈpiːdɪk/

orthopedic

骨や筋肉の変形の修正に関連する
Meaning
Relating to the correction of deformities of bones or muscles.
Example
She visited an orthopedic surgeon for her back pain.
彼女は背中の痛みのために整形外科医に行った。
C1 verb /ˈɒs.ɪ.leɪt/

oscillate

二つの点または状態の間で前後に動くまたは揺れる
Meaning
To swing or move back and forth between two points or states
Example
The stock market tends to oscillate during uncertain times.
株式市場は不確実な時期に振動しがちです。
B2 noun /ɔːrˈɡæn.ɪk ˈfɑːr.mɪŋ/

organic farming

有機農業
Meaning
Farming method that avoids synthetic chemicals and fertilizers, using natural methods instead.
Example
Organic farming improves soil health and reduces pollution.
オーガニックファーミングは土壌の健康を改善し、汚染を減らします。
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。
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.
C1 noun /oʊθ/

Oath

誓い
Meaning
a solemn promise or declaration; a sworn statement
Example
The doctor took an oath to help patients.
医師は患者を助けることを誓いました。
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。
C1 noun /ˈɑːlɪˌɡɑːrki/

oligarchy

寡頭政治
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.
その国は裕福なオリガーキーによって支配され、すべての資源を支配していました。
C2 noun /ˈɒksɪdənt/

occident

西洋
Meaning
The countries of the West, especially Europe and America.
Example
The Occident has a long history of philosophical thought.
西洋には長い哲学的思考の歴史があります。
A2 verb /ˈɔːfər/

offer

申し出る
Meaning
to present something for acceptance or rejection; to propose
Example
She offered to help with the project.
彼女はプロジェクトを手伝うと申し出た。
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。
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 /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。
C1 adjective /ˈɔːrθədɑːks/

orthodox

Meaning
conforming to traditional beliefs or practices
Example
He comes from a very orthodox family.
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。
B2 noun /ˈɒfərɪŋ/

offering

オファリング
Meaning
something that is given, especially as a gift or contribution
Example
The company’s latest offering is an eco-friendly car.
会社の最新のオファリングは、エコフレンドリーな車です。
A2 noun əˈlɪm.pɪk ɡeɪmz

Olympic Games

オリンピック競技大会
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.
オリンピック競技大会は世界のトップアスリートを集めます。
B2 adjective /ˈɔː.də.li/

Orderly

整然とした; 系統的な; 平和的な
Meaning
well-organized; systematic; peaceful
Example
Please keep your desk orderly and clean.
デスクを整然とした状態できれいに保ってください。
A2 adverb; noun /ˌaʊtˈdɔːrz/

outdoors

屋外で
Meaning
outside a building; the natural environment outside
Example
We spent the whole afternoon outdoors enjoying the fresh air.
私たちは午後ずっと屋外で新鮮な空気を楽しみました。
C1 noun /oʊˈmɪʃ.ən/

Omission

省略; 除外
Meaning
the action of excluding or leaving out someone or something; a failure to include
Example
The omission of his name from the list was intentional.
リストから彼の名前を省略することは意図的でした。
B1 adjective /ˌoʊld ˈfæʃənd/

old-fashioned

昔風の
Meaning
not modern; belonging to an earlier time
Example
He still wears an old-fashioned hat.
彼は今でも昔風の帽子をかぶっています。
C2 adjective /ˈɑːbdjʊrət/

obdurate

頑固
Meaning
Stubbornly refusing to change one's opinion or course of action.
Example
He remained obdurate despite everyone's pleas.
彼は皆の懇願にもかかわらず、頑固なままでした。
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。
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.
B2 adjective /ˈɒp.ʃən.əl/

Optional

任意
Meaning
not compulsory; left to choice
Example
Wearing a tie is optional for this event.
このイベントではネクタイの着用は任意です。
C2 noun /əˈblɪkwɪti/

obliquity

歪み
Meaning
Deviation from moral or usual conduct; indirectness or lack of straightforwardness.
Example
The politician was criticized for the obliquity of his answers.
その政治家は、彼の答えの歪みについて批判された。
C1 adjective /əˈblaɪdʒɪŋ/

obliging

親切な
Meaning
Willing to help or do favors; accommodating.
Example
The staff at the hotel were very obliging and friendly.
ホテルのスタッフはとても親切で友好的でした。
B1 noun /aʊl/

Owl

フクロウ
Meaning
a nocturnal bird of prey with large eyes and a hooked beak
Example
The owl hooted softly in the darkness of the forest.
フクロウは森の暗闇で静かに鳴いた。
C2 adjective /ɑːlˈfæktəri/

olfactory

Meaning
Relating to the sense of smell.
Example
The perfume activated her olfactory nerves immediately.
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。
A1 verb, adjective /oʊn/

own

所有する
Meaning
to possess something; belonging to oneself
Example
She owns a beautiful house in the city.
彼女は市内に美しい家を持っています。
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 adjective /ˈoʊdiəs/

odious

忌まわしい
Meaning
extremely unpleasant or repulsive
Example
The dictator was remembered for his odious crimes.
その独裁者は彼の忌まわしい犯罪で記憶されました。
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。
B2 verb /oʊˈmɪt/

omit

省略する
Meaning
to leave out or exclude; to fail to include something
Example
Please don't omit any important details from your report.
レポートから重要な詳細を省略しないでください。
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 verb /əbˈstrʌkt/

obstruct

妨げる
Meaning
to block or hinder progress; to prevent or impede movement
Example
The fallen tree obstructed the road for several hours.
倒れた木が数時間道路をふさぎました。
C1 adjective /ˈɒm.ɪ.nəs/

Ominous

不吉な; 脅威の
Meaning
giving the impression that something bad will happen; threatening; foreboding
Example
The dark clouds looked ominous before the storm.
嵐の前に、暗い雲は不吉に見えました。
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。
B1 adjective /əˈrɪdʒ.ɪ.nəl/

Original

元の; 基本的な; 本物の
Meaning
first; fundamental; primary; authentic
Example
This is the original document, not a copy.
これはオリジナルの文書で、コピーではありません。
C2 verb /ˈɔːreɪt/

orate

演説する
Meaning
To speak in a formal, often pompous manner
Example
He began to orate at the ceremony.
彼は式で演説を始めました。
B2 noun /ˈaʊtˌfɪt/

outfit

衣装
Meaning
A set of clothes worn together, often for a particular occasion.
Example
She wore a beautiful outfit to the party.
彼女はパーティーに美しい衣装を着て行った。
C1 adjective /ˌaʊtˈlændɪʃ/

outlandish

奇妙
Meaning
Looking or sounding bizarre or unfamiliar; strange.
Example
He wore an outlandish costume to the festival.
彼は祭りに奇妙な衣装を着ていました。
C2 noun /ˈoʊ.kəm/

oakum

古いロープの繊維
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.
船大工たちは木の板の隙間を塞ぐためにオーカムを使いました。
B2 noun /ˌɒpəˈzɪʃən/

opposition

反対
Meaning
the action of opposing or resisting something
Example
The opposition to the new law was strong.
新しい法律に対する反対は強かった。
C1 verb /ˌoʊvərˈriːtʃ/

overreach

過剰な努力
Meaning
to go beyond what is proper, acceptable, or achievable; to overextend
Example
The politician overreached by making promises he couldn't keep.
その政治家は約束を守れなかったことで過剰な努力をしました。
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。
C1 adjective /ˌɒstɛnˈteɪʃəs/

ostentatious

見せびらかしの
Meaning
Characterized by a showy or pretentious display intended to impress others.
Example
He wore an ostentatious gold chain to the party.
彼はパーティーで見せびらかしの金のチェーンをしていました。
B2 noun/verb /ˈaʊtreɪdʒ/

outrage

憤慨
Meaning
A strong feeling of anger and shock; to arouse anger or shock.
Example
The unfair decision caused public outrage.
不公平な決定が公共の憤慨を引き起こしました。
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。
C2 noun /oʊliˈændər/

Oleander

オレアンダー
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.
美しいオレアンダーの花が庭で咲いていましたが、その毒性に関わらず。
C2 noun /ˈɔː.rɪ.fɪs/

orifice

孔
Meaning
an opening or hole, especially in the body or a device
Example
The medicine was applied through a small orifice in the device.
薬は装置の小さな孔から適用されました。
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。
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。
C1 noun ɔːrˈdiːl

ordeal

厳しい試練
Meaning
A physical or mental painful experience that must be endured
Example
Surviving the wilderness was a tough ordeal for them.
荒野で生き残ることは彼らにとって大変な試練でした。
B2 adjective + noun ˈɒptɪməl ˈtempərətʃər

optimal temperature

最適温度
Meaning
The best or most favorable temperature for a particular purpose
Example
Winter provides optimal temperature for farming.
冬は農業に最適な温度を提供します。
B2 adjective /aʊtˈreɪdʒəs/

outrageous

ショッキング
Meaning
Shockingly bad or excessive; very unusual or amusing.
Example
The comedian told an outrageous joke.
コメディアンはショッキングなジョークを言いました。
C1 noun ˈoʊʃən əˌsɪdɪfɪˈkeɪʃən

ocean acidification

海洋酸性化
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.
海洋酸性化は、大気中のCO2の吸収によって引き起こされます。
C2 adjective /ˈɒsiəs/

osseous

骨のような
Meaning
consisting of or turned into bone; bony
Example
The fossil showed osseous structures of the ancient creature.
化石は古代の生物の骨のような構造を示しました。
C2 adjective /əbˈsiːkwɪəs/

obsequious

お世辞
Meaning
Excessively obedient or attentive in a servile way.
Example
The waiter gave an obsequious bow to every customer.
ウェイターは各顧客にお世辞のようなお辞儀をしました。
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。
B1 noun ˌɒpəˈtjuːnɪtiz

opportunities

チャンス
Meaning
A set of circumstances that makes it possible to do something; chances for advancement or success.
Example
Opportunities for jobs decreased.
仕事のチャンスが減少しました。
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。
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。
C1 adjective /ˌəʊ.vərˈɑː.tʃɪŋ/

overarching

全体的な, 包括的な, 包み込む
Meaning
Comprehensive or all-embracing; forming an arch over something.
Example
The overarching theme of the book is human resilience.
その本の大きなテーマは人間の回復力です。
B2 verb /ˌoʊvərˈsiː/

oversee

監督する
Meaning
to supervise or watch over something; to manage and direct
Example
The manager will oversee the entire construction project.
マネージャーは全体の建設プロジェクトを監督します。
C2 adjective /ˈoʊ.pən ˈhɑrt.ɪd/

Open-hearted

オープンハート; 寛大で誠実; 心温かく受け入れる;
Meaning
Kind and generous; sincere and honest; warmly receptive;
Example
She welcomed the strangers with an open-hearted smile and invited them for dinner.
彼女は見知らぬ人々を心温かい笑顔で迎え、夕食に招待した。
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。
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。
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 /ˌɑːpərˈtuːnɪst/

opportunist

機会主義者
Meaning
A person who takes advantage of situations for personal gain, often disregarding principles.
Example
He is seen as an opportunist who always puts his interests first.
彼は常に自分の利益を第一に考える機会主義者として見られています。
B2 verb /əˈfend/

offend

侮辱する
Meaning
to cause displeasure or resentment; to hurt someone's feelings
Example
His rude comments offended many people at the meeting.
彼の無礼なコメントは会議で多くの人々を怒らせました。
B2 verb /ˌoʊvərˈtɜrn/

overturn

覆す / 判決を覆す
Meaning
to turn something upside down or to reverse a decision or judgment
Example
The court decided to overturn the previous ruling.
裁判所は前回の判決を覆すことに決めました。
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 noun /ˈaʊtɪŋ/

outing

お出かけ
Meaning
a short trip or excursion, often for leisure or enjoyment
Example
They had a lovely outing at the beach last weekend.
彼らは先週末、ビーチで素晴らしいお出かけをしました。
C2 verb ˈɑːb.fə.skeɪt

obfuscate

曖昧にする、混乱させる、隠す
Meaning
Render obscure, unclear, or unintelligible.
Example
Politicians often obfuscate facts to mislead people.
政治家はしばしば事実をわかりにくくして人々を誤導します。
C1 noun /əbˈdʒɛktər/

objector

反対者
Meaning
a person who expresses opposition or disapproval to something
Example
The objector raised his concerns during the town meeting.
反対者は市議会の会議中に自分の懸念を表明しました。
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.
C1 noun /ˈoʊvərˌtʊr/

overture

序曲 / 提案
Meaning
An introduction to something more substantial; a proposal or preliminary action.
Example
The peace overture was welcomed by both nations.
平和提案は両国によって歓迎されました。
C2 noun /ˈoʊvərlɔːrd/

overlord

領主
Meaning
A ruler, master, or person of great power and authority over others.
Example
The peasants were forced to pay taxes to their overlord.
農民たちは自分たちの領主に税金を払うよう強制されました。
B2 noun /ˈɔr.fən/

Orphan

孤児
Meaning
a child whose parents are dead; someone without protective support
Example
The orphan was adopted by a loving family.
その孤児は愛情深い家族に養子として迎えられました。
B2 noun /ɒpˈtɪʃən/

optician

眼鏡技師
Meaning
A person who makes or sells glasses and contact lenses.
Example
The optician adjusted my new glasses to fit better.
オプティシャンは私の新しい眼鏡をより良くフィットするように調整しました。
B2 noun /ˌoʊ.vɚˈkraʊ.dɪŋ/

overcrowding

過密
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.
地下鉄システムはピーク時にひどい過密状態に苦しんでいます。
C2 noun /ˈɒfərtɔːri/

offertory

奉納
Meaning
The part of a religious service when offerings are collected; the offering itself.
Example
The offertory was taken during the Sunday service.
日曜日の礼拝中に奉納が取られました。
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。
C2 verb /ˈɑːbdʒərˌɡeɪt/

objurgate

厳しく叱る
Meaning
to scold or rebuke severely
Example
The teacher objurgated the student for being dishonest.
先生は不正直な生徒を厳しく叱った。
C2 noun /ˌɔːrdɪˈneɪʃən/

ordination

任命式
Meaning
The ceremony of conferring holy orders or official religious authority.
Example
The church held a special service for the ordination of new priests.
教会は新しい神父の任命のために特別なサービスを行いました。
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。
C2 verb /ˈɑːbvieɪt/

obviate

排除する
Meaning
To remove a need or difficulty; to prevent or avoid something.
Example
This new system obviates the need for manual data entry.
この新しいシステムは手動データ入力の必要性を排除します。
C2 noun /ɒkˈteɪvoʊ/

octavo

オクターヴォ (紙を8つに折りたたんで作られた本のサイズ)
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.
古い図書館にはシェイクスピアの珍しいオクターヴォ版がありました。
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。
A1 adverb /ˈɔːfən/

often

しばしば
Meaning
frequently, many times
Example
I often visit my grandparents on weekends.
私は週末にしばしば祖父母を訪れます。
C1 adjective /ˌaʊtˈspoʊkən/

Outspoken

率直
Meaning
frank; speaking directly
Example
She is known for being outspoken about social issues.
彼女は社会問題について率直に話すことで知られています。
B2 noun /əbˈzɜːvər/

observer

観察者
Meaning
a person who watches or notices something
Example
The observer took notes during the meeting.
観察者は会議中にメモを取った。