radioactivity
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B2 noun ˌreɪ.di.oʊ.ækˈtɪv.ə.ti

radioactivity

放射性
Meaning
The emission of ionizing radiation or particles caused by the spontaneous disintegration of atomic nuclei.
Example
Radioactivity is used in medical treatments like cancer therapy.
放射性は、がん治療のような医療に用いられている。
B2 adjective ˌrev.əˈluː.ʃən.ər.i

revolutionary

革命的な
Meaning
Involving or causing a complete or dramatic change.
Example
Revolutionary ideas are reshaping the industry.
革命的なアイデアが業界を再編成しています。
B2 noun /rɪˈvendʒ/

Revenge

復讐
Meaning
the action of inflicting hurt or harm on someone for an injury or wrong suffered at their hands
Example
She sought revenge against those who betrayed her trust.
彼女は信頼を裏切った者たちに復讐を求めた。
B2 verb /ˌriːprəˈdjuːs/

reproduce

再生する, 繁殖する
Meaning
To make a copy of something; to generate offspring.
Example
Many animals reproduce rapidly in favorable conditions.
多くの動物は好ましい条件下で急速に繁殖します。
B2 noun /rɪˈlaɪ.əns/

Reliance

依存
Meaning
the state of depending on something or someone for support or help
Example
His reliance on technology is concerning.
技術への依存は懸念すべきことです。
B2 adjective /ˈrændəm/

Random

ランダム
Meaning
without pattern or predetermined order; happening by chance
Example
She selected a random book from the library shelf.
彼女は図書館の棚からランダムに本を選びました。
B2 adjective /rɪˈzɪl.i.ənt/

resilient

回復力のある
Meaning
Able to withstand or recover quickly from difficult conditions.
Example
Resilient materials ensure durability.
回復力のある素材は耐久性を保証します。
B2 noun /rɪˈstrɪk.ʃən/

Restriction

制限; 限界; コントロール
Meaning
a limiting condition or measure; the limitation or control of someone or something
Example
There are strict restrictions on smoking in public places.
公共の場所での喫煙には厳格な制限があります。
B2 noun /ˈrem.ə.di/

Remedy

薬; 治療; 問題解決の手段
Meaning
a medicine or treatment for a disease; a solution to a problem
Example
This herbal remedy helps with headaches.
このハーブの薬は頭痛に効く。
B2 noun /rʌʃ/

Rush

急ぎ; ラッシュ
Meaning
a sudden quick movement toward something; a period of great activity or demand; hurry
Example
There was a rush to buy tickets for the concert.
コンサートのチケットを買うために急いでいました。
B2 noun /ˌrɛvəˈleɪʃən/

revelation

啓示
Meaning
A surprising and previously unknown fact, especially one made known in a dramatic way.
Example
The book was full of shocking revelations about the politician.
その本はその政治家に関する衝撃的な啓示で満ちていました。
B2 noun /ˈraɪfəl/

Rifle

ライフル
Meaning
a gun with a long barrel that is fired from the shoulder
Example
The soldier carried a rifle during the mission.
兵士は任務中にライフルを携帯していました。
B2 verb /ˌriːəˈʃʊr/

reassure

安心させる
Meaning
to say or do something to remove someone's doubts or fears
Example
The teacher reassured the students before the exam.
教師は試験前に生徒を安心させました。
B2 noun /rɪˈfreʃ.mənt/

Refreshment

軽食
Meaning
food and drink that is served as a light meal; something that refreshes
Example
We served light refreshments after the meeting.
会議の後、軽食を提供しました。
B2 noun /ˌren.əˈveɪ.ʃən/

Renovation

リノベーション; 改修
Meaning
the act of renovating; restoration to a former better state
Example
The old house underwent a complete renovation last year.
その古い家は昨年完全な改修を受けました。
B2 noun /ˈraɪvəl/

Rival

ライバル; 競争相手;
Meaning
a person or thing competing with another for the same objective or for superiority in the same field
Example
The two companies have been business rivals for decades.
二つの企業は何十年もの間、商業上のライバルです。
B2 noun /ˈroʊstɪd miːt/

Roasted meat

ロースト肉
Meaning
meat cooked by dry heat in an oven or over fire
Example
The roasted meat was perfectly seasoned and tender.
ロースト肉は完璧に調味され、柔らかかった。
B2 noun /rɪb/

Rib

あばら骨
Meaning
one of the curved bones that protect the chest and lungs
Example
He broke his rib in the accident.
彼は事故であばら骨を折った。
B2 verb /ˌriːjuˈnaɪt/

reunite

再会する
Meaning
to bring together again after separation
Example
The family was reunited after many years.
その家族は何年も後に再会しました。
B2 noun /ˈraɪvəlri/

Rivalry

ライバル関係; 競争
Meaning
competition for the same objective or for superiority in the same field; the state of being rivals
Example
The rivalry between the two teams made the match exciting.
二つのチーム間のライバル関係が試合を興奮させた。
B2 adjective /ˈrɪtʃ.u.əl/

Ritual

儀式
Meaning
relating to religious or ceremonial practices
Example
The wedding ceremony included many traditional ritual elements.
結婚式では多くの伝統的な儀式が行われました。
B2 noun /ˈrɛnəˌsɑːns/

renaissance

ルネサンス
Meaning
a revival of art, culture, or learning; a period of renewed interest and growth
Example
The city experienced a cultural renaissance during the 1990s.
その都市は1990年代に文化的なルネサンスを経験しました。
B2 noun, verb /ræŋks/

ranks

ランク
Meaning
Positions within a group, especially in a hierarchy or organization.
Example
He quickly moved up the ranks of the army.
彼はすぐに軍隊のランクで上昇しました。
B2 adjective /rɪˈzɪstənt/

resistant

耐性
Meaning
not affected by something; able to oppose or withstand
Example
This fabric is resistant to water and stains.
この布は水と汚れに強いです。
B2 verb /rɪˈtriːv/

retrieve

取り戻す
Meaning
to get something back that was lost or taken; to recover
Example
She managed to retrieve her lost phone from the taxi.
彼女はタクシーから失われた電話を取り戻すことができました。
B2 noun rɪˈkruːt.mənt

recruitment

採用
Meaning
The action of finding new people to join an organization or support a cause.
Example
Recruitment strengthens the workforce.
採用は労働力を強化します。
B2 noun /ˈrʊki/

rookie

初心者
Meaning
a person who is new to an activity or organization; a beginner
Example
The rookie policeman made a few mistakes on his first day.
新米警官は初日にいくつかのミスを犯しました。
B2 verb /ˈrɛnəˌveɪt/

renovate

改装する
Meaning
to restore something old to a good state or to improve it
Example
They decided to renovate the old house before moving in.
彼らは引っ越す前に古い家を改装することに決めました。
B2 verb /ˈreɪn.dʒɪŋ/

ranging

変動する
Meaning
Extending or varying between limits.
Example
The temperatures are ranging from 15 to 30 degrees this week.
今週の気温は15度から30度の間で変動しています。
B2 verb /ˌriːkriˈeɪt/

recreate

再創造する
Meaning
to create or produce something again, especially a new version of something lost or destroyed
Example
The team recreated the lost dataset from backups.
チームはバックアップから失われたデータセットを再作成しました。
B2 verb /reɪl/

rail

抗議する
Meaning
to complain or protest strongly about something
Example
He railed against the unfair decision.
彼は不公平な決定に対して強く抗議した。
B2 adjective /rɪˈzɜːrvd/

Reserved

控えめな; 内向的な
Meaning
slow to reveal emotion or opinions; restrained in manner
Example
She is quite reserved and doesn't talk much in meetings.
彼女はかなり控えめで、会議ではあまり話しません。
B2 noun ˌrɛstəˈreɪʃən

restoration

修復
Meaning
The process of returning something to its former condition.
Example
The restoration of the forest began after decades of neglect.
森林の修復は数十年の放置後に始まりました。
B2 noun, verb /ˈriːteɪl/

retail

小売
Meaning
the sale of goods to the public in small quantities for use or consumption rather than for resale
Example
The company specializes in the retail of clothing and accessories.
この会社は衣類とアクセサリーの小売を専門としています。
B2 noun ˈrɛstɪŋ pleɪs

resting place

安息地
Meaning
A place where someone or something rests, especially a burial site.
Example
The resting place of the martyrs is near the river.
殉教者の安息地は川の近くにあります。
B2 verb /rɪˈtriːt/

retreat

撤退する
Meaning
to move back or withdraw from a position or situation
Example
The soldiers had to retreat after losing the battle.
兵士たちは戦いに負けた後、撤退しなければならなかった。
B2 noun /rɪˈmuː.vəl/

Removal

撤去; 除去; 解雇;
Meaning
the action of taking something away or eliminating it; dismissal from office
Example
The removal of the old furniture took all day.
古い家具の除去に一日中かかりました。
B2 verb /ˈræm.bəl/

ramble

Meaning
to talk or write at length in a confused or inconsequential way; to walk for pleasure without a fixed route.
Example
He rambled on about his childhood for hours.
B2 noun /rɪˈfɔːr.mər/

Reformer

改革者
Meaning
a person who works to bring about positive changes in society or institutions
Example
The social reformer dedicated her life to improving education for all children.
社会的な改革者は、すべての子供たちの教育を改善するために自分の人生を捧げました。
B2 verb /ˌriːəˈreɪndʒ/

rearrange

再配置する
Meaning
to change the order or position of something
Example
She decided to rearrange the furniture in her living room.
彼女はリビングルームの家具を再配置することに決めました。
B2 adjective /rɪˈliːvd/

relieved

安心した
Meaning
feeling happy and less worried after something stressful has been removed or resolved
Example
She felt relieved after hearing the good news.
良い知らせを聞いた後、彼女は安心した。
B2 adjective /rɪˈnjuː.ə.bəl/

renewable

再生可能
Meaning
Able to be renewed or replaced naturally; not depleted when used.
Example
Renewable resources minimize environmental damage.
再生可能な資源は環境へのダメージを最小限に抑えます。
B2 noun /ˈraɪət/

Riot

暴動; 騒乱
Meaning
a violent disturbance of the peace by a crowd; an uncontrolled outburst
Example
The peaceful protest turned into a riot when violence broke out.
平和的な抗議は暴力が起こったときに暴動に変わった。
B2 noun rɪˈzentmənt

resentment

憤り
Meaning
Bitter indignation at having been treated unfairly.
Example
Resentment grew among the students.
学生の間で憤りが増大した。
B2 verb /rɪˈvaɪv/

revive

蘇生する
Meaning
To bring back to life, consciousness, or activity.
Example
The paramedics managed to revive the unconscious man.
救急隊員は意識不明の男性を蘇生させることに成功した。
B2 verb /rɪˈliːv/

relieve

Meaning
to make pain, distress, or difficulty less severe or serious
Example
The medicine helped relieve his headache.
B2 noun /ˈruːlɪŋ/

ruling

判決
Meaning
an official decision made by a judge or authority.
Example
The court’s ruling favored the defendant.
裁判所の判決は被告に有利でした。
B2 verb /roʊm/

roam

歩き回る
Meaning
to walk or travel without a specific destination; to wander
Example
Wild animals roam freely in the forest.
野生動物は森の中を自由に歩き回っています。
B2 noun /ˈrɪə.lɪ.zəm/

realism

リアリズム
Meaning
The quality of representing things as they are; a practical or factual view.
Example
Her paintings are admired for their realism.
彼女の絵画はそのリアリズムで賞賛されています。
B2 adverb /ruːˈtiːnli/

routinely

定期的に
Meaning
as part of a regular procedure; habitually
Example
The staff routinely checks the equipment for safety.
スタッフは定期的に安全のために機器を点検します。
B2 noun /rɪˈdʒɛkʃən/

rejection

拒絶
Meaning
the action of refusing or dismissing something or someone
Example
Her rejection of the offer surprised everyone.
彼女の提案の拒絶は皆を驚かせた。
B2 adjective /rɪˈspek.tə.bəl/

Respectable

尊敬すべき
Meaning
worthy of respect; having good reputation; decent
Example
He comes from a respectable family in the community.
彼は地域社会の尊敬すべき家族から来ました。
B2 adjective /ˈrɪdən/

ridden

覆われた
Meaning
Full of or dominated by something unpleasant.
Example
The country was ridden with corruption.
その国は腐敗に覆われていた。
B2 noun /rɪˈlʌk.təns/

Reluctance

嫌悪感; ためらい
Meaning
unwillingness to do something; hesitation
Example
He showed reluctance to accept the job offer.
彼は仕事のオファーを受け入れることに嫌悪感を示した。
B2 noun /ˈrækɪt/

racket

ラケット / 騒音
Meaning
A piece of equipment used to hit the ball in sports like tennis or badminton; also a loud noise or an illegal scheme.
Example
He bought a new tennis racket for the match.
彼は試合のために新しいテニスラケットを買った。
B2 verb /rɪˈstrɪkt/

restrict

制限する
Meaning
To limit the size, amount, or range of something.
Example
The government decided to restrict the use of plastic bags.
政府はプラスチック袋の使用を制限することを決定しました。
B2 noun rɪˈzɪl.i.əns

resilience

レジリエンス
Meaning
The ability to recover quickly from difficulties; toughness.
Example
Testing the resilience of wood is crucial.
木材のレジリエンスをテストすることは非常に重要です。
B2 noun /rɪˈsiː.vər/

Receiver

受話器
Meaning
a person or thing that receives something; the part of a telephone containing the earpiece and mouthpiece
Example
She picked up the receiver to answer the phone call.
彼女は電話に出るために受話器を取った。
B2 noun /ˌriː.ɪnˈfɔːrs.mənt/

reinforcement

強化
Meaning
Strengthening or supporting something, especially behavior or learning.
Example
Positive reinforcement helps in learning.
積極的な強化は学習に役立ちます。
B2 noun, verb /ˈrætəl/

rattle

ガタガタ鳴る；ガラガラ
Meaning
to make a rapid series of short, sharp sounds; a device or object that makes such a sound
Example
The loose window began to rattle in the strong wind.
強い風で緩んだ窓がガタガタ鳴り始めた。
B2 noun /ˈrest.ləs.nəs/

Restlessness

不安
Meaning
the inability to rest or relax as a result of anxiety or boredom
Example
His restlessness during the long meeting was obvious to everyone.
長い会議中、彼の不安は全員に明らかだった。
B2 adjective /ˈrɪɡ.ər.əs/

rigorous

厳格な
Meaning
Extremely thorough and demanding in analysis or practice.
Example
A rigorous study plan helps students achieve better results.
厳格な学習計画は、学生がより良い結果を得るのに役立ちます。
B2 adjective /ˈruː.mi/

Roomy

広々とした; 広いスペースのある
Meaning
spacious; having a lot of room
Example
The apartment is very roomy with spacious bedrooms.
アパートメントは広々としており、広いベッドルームがあります。
B2 verb /rɪˈkʌvərɪŋ/

recovering

回復
Meaning
the process of getting better after illness, loss, or difficulty
Example
She is still recovering from the flu.
彼女はまだインフルエンザから回復しています。
B2 adjective /ˈreɪʃəl/

racial

人種の
Meaning
relating to a race of people
Example
Racial equality is an important issue in many societies.
人種平等は多くの社会において重要な問題です。
B2 verb /rɪˈdʒɔɪs/

rejoice

喜ぶ
Meaning
to feel or show great joy; to celebrate
Example
The family rejoices at the good news.
その家族は良いニュースに喜んでいます。
B2 noun /ˈreɪn.dʒər/

ranger

レンジャー
Meaning
A person responsible for protecting and managing forests, parks, or natural areas.
Example
The park ranger guided the tourists through the forest trail.
公園のレンジャーは観光客を森の小道を案内しました。
B2 noun /ˈræŋkɪŋ/

ranking

ランキング
Meaning
a position in a list or hierarchy, especially in terms of performance or importance
Example
His ranking in the competition improved after each round.
彼の競技でのランキングは、各ラウンド後に向上しました。
B2 adjective /raɪp/

Ripe

熟した; 食べる準備ができた
Meaning
fully developed and ready to eat; mature; ready for action or use
Example
The bananas are ripe and ready to eat.
バナナは熟して食べる準備ができています。
B2 noun /ˌriː.əˈʃʊr.əns/

Reassurance

安心
Meaning
comfort or confidence given to someone to remove their fears or doubts
Example
She needed reassurance that everything would be okay.
彼女はすべてがうまくいくことを確認するために安心が必要でした。
B2 noun /ˌrɛprɪzɛnˈteɪʃən/

representation

代表
Meaning
the action of speaking or acting on behalf of someone or something
Example
Her representation of the team was impeccable.
彼女のチームの代表は完璧でした。
B2 noun /ˈrep.taɪl/

Reptile

爬虫類
Meaning
a cold-blooded animal with scaly skin that lays eggs on land
Example
The lizard is a common reptile found in gardens.
トカゲは庭で見られる一般的な爬虫類です。
B2 noun rɪˈpʌb.lɪk

republic

共和国
Meaning
A state in which supreme power is held by the people and their elected representatives, with an elected or nominated president rather than a monarch.
Example
A republic is governed by representatives of the people.
共和国は人民の代表者によって治められています。
B2 noun /rɪˈbel.jən/

Rebellion

反乱
Meaning
an act of armed resistance to an established government or leader
Example
The rebellion against the king lasted for three years.
王に対する反乱は3年間続いた。
B2 noun, verb /ræmp/

ramp

ランプ
Meaning
a sloping surface joining two different levels; as a verb, to increase or rise sharply
Example
The car drove up the ramp into the parking garage.
車は駐車場のランプを上がった。
B2 noun /ˌreɡ.jʊˈlær.ɪ.ti/

Regularity

規則正しさ
Meaning
the quality of being regular; occurring at fixed intervals or in a consistent pattern
Example
The regularity of his exercise routine helped him stay healthy.
彼の運動習慣の規則正しさが健康を維持するのに役立ちました。
B2 noun /'ræd.ɪʃ/

Radish

ラディッシュ
Meaning
a small pungent edible root vegetable with white or red skin
Example
The farmer harvested fresh radishes from the garden.
農家は庭から新鮮なラディッシュを収穫しました。
B2 verb /ˈruːɪn/

ruin

台無しにする
Meaning
to destroy or damage beyond repair; to spoil completely
Example
Heavy rain could ruin our picnic plans.
強い雨が私たちのピクニックの計画を台無しにするかもしれません。
B2 noun /rɪˈsɪp.i.ənt/

Recipient

受取人
Meaning
a person who receives something
Example
She was the recipient of the prestigious award.
彼女はその名誉ある賞の受取人でした。
B2 noun, verb /rɪər/

rear

後ろ / 育てる
Meaning
the back part of something; to bring up or raise children or animals
Example
The mother cat reared her kittens in a quiet corner.
母猫は静かな隅で子猫たちを育てました。
B2 adjective /ˈrʌn daʊn/

run-down

荒れ果てた
Meaning
in a poor condition; worn out or neglected
Example
They live in a run-down house at the edge of town.
彼らは町の端にある荒れ果てた家に住んでいます。
B2 adjective /ˈroʊlɪŋ/

rolling

転がる
Meaning
moving in gentle undulations; moving forward by turning over and over
Example
They drove through the rolling hills of the countryside.
彼らは田舎の転がる丘を通り抜けました。
B2 verb rɪˈzaɪn

resign

辞任する
Meaning
Voluntarily leave a job or other position.
Example
Ministers were forced to resign.
大臣たちは辞任を余儀なくされました。
B2 verb /rɒt/

rot

腐る
Meaning
to decay or decompose; to become corrupt
Example
The fruit will rot if left in the sun.
果物は日光に当たると腐ります。
B2 adjective /ˈrest.ləs/

Restless

落ち着きのない
Meaning
unable to rest or relax; constantly moving or fidgeting
Example
The child was restless during the long car journey.
長い車の旅で子供は落ち着きがなかった。
B2 verb /rɪˈkɔːl/

recall

思い出す
Meaning
to bring (a memory, fact, or situation) back into one's mind
Example
I can't recall the last time we met.
最後に会った時のことを思い出せません。
B2 noun rɪsk ˈfæktər

risk factor

リスク要因
Meaning
Something that increases the likelihood of developing a disease or condition
Example
Water pollution is a significant risk factor for health.
水質汚染は健康にとって重要なリスク要因です。
B2 noun /reɪˈʒiːm/

regime

政権
Meaning
a system or form of government, often authoritarian
Example
The military regime controlled the country for decades.
軍事政権は数十年間国を支配していました。
B2 noun ˌriːkənˈstrʌkʃn

reconstruction

再建
Meaning
The action or process of reconstructing or being reconstructed.
Example
The reconstruction project took years.
再建プロジェクトは数年かかりました。
B2 noun /rʌst/

Rust

錆
Meaning
reddish-brown coating formed on iron or steel by oxidation; corrosion
Example
The old car was covered in rust after years of neglect.
古い車は何年も放置されていた後、サビで覆われていました。
B2 noun /ˌriːprəˈdʌkʃən/

reproduction

再生, 繁殖
Meaning
The process of producing offspring; the act of copying or duplicating.
Example
The textbook included a detailed diagram of human reproduction.
教科書には人間のリプロダクションの詳細な図が含まれていました。
B2 verb /rɪˈsaɪt/

recite

暗唱する
Meaning
To say aloud something learned, especially poetry or text, from memory.
Example
The child recited a poem in front of the class.
その子はクラスの前で詩を暗唱しました。
B2 noun /ˈrɛfjuːdʒ/

refuge

避難所
Meaning
a place that provides shelter or protection from danger or distress
Example
The villagers took refuge in the temple during the storm.
村人たちは嵐の間、寺院に避難した。
B2 noun /ˈreɪʃoʊ/

ratio

比率
Meaning
a relationship between two numbers showing how many times the first number contains the second
Example
The ratio of boys to girls in the class is 2:1.
クラスでの男の子と女の子の比率は2:1です。
B2 noun ˌriːfɔːˈreɪʃən

reforestation

再植林
Meaning
The natural or intentional restocking of existing forests and woodlands that have been depleted.
Example
Reforestation efforts are crucial to restoring ecosystems.
再植林の努力は、生態系の回復に重要です。
B2 verb /rɪˈkleɪm/

reclaim

Meaning
To take back or recover something; to restore to a usable state.
Example
The farmer worked to reclaim the barren land.
B2 noun /ræɡ/

Rag

古い布; 掃除に使われる擦り切れた衣類
Meaning
a piece of old cloth used for cleaning; worn-out clothing
Example
She used an old rag to clean the dusty table.
彼女は古い布を使って、ほこりだらけのテーブルを掃除しました。
B2 adjective /ræʃ/

rash

軽率, 無謀
Meaning
Acting quickly without careful consideration; reckless.
Example
It was a rash decision to invest without research.
調査なしで投資するのは無謀な決断だった。
B2 noun /ˈrerəti/

Rarity

珍しい状態; 普通でないもの、または希少なもの
Meaning
the state of being rare; something that is uncommon or scarce
Example
The antique vase was a rarity worth thousands of dollars.
その古代の花瓶は、数千ドルの価値がある珍しいものだった。
B2 noun /ˈroʊ.lɪŋ pɪn/

Rolling pin

めん棒
Meaning
a cylindrical tool used for rolling out dough or pastry
Example
Roll the dough flat with a rolling pin.
めん棒で生地を広げてください。
B2 adjective /rɪˈflektɪv/

Reflective

反射的; 思慮深い; 光や画像を反射できる
Meaning
thoughtful; contemplative; able to reflect light or images
Example
After the meeting, he was in a reflective mood.
会議の後、彼は反射的な気分だった。
B2 adverb /rɪˈmɑːrkəbli/

remarkably

驚くべき方法で
Meaning
in a way that is worthy of attention or notice; surprisingly
Example
She did remarkably well in the competition.
彼女はコンペティションで驚くべき成果を上げました。
B2 noun /ˈraɪdər/

rider

ライダー
Meaning
A person who rides a horse, bicycle, motorcycle, or other vehicle.
Example
The rider fell off the horse.
ライダーは馬から落ちました。
B2 adjective /rɪˈsɔːrsfəl/

resourceful

Meaning
Having the ability to find quick and clever ways to overcome difficulties.
Example
She is very resourceful when it comes to solving unexpected problems.
B2 adjective /ˈrɒt.ən/

Rotten

腐った; 悪い
Meaning
decayed; spoiled; bad
Example
The apple is rotten and should be thrown away.
リンゴは腐っていて、捨てるべきです。
B2 noun /ˈruːdnəs/

Rudeness

無礼
Meaning
the quality of being impolite, discourteous, or offensive in behavior or speech
Example
His rudeness shocked everyone at the dinner party.
彼の無礼さはディナーパーティーで皆を驚かせました。
B2 verb /rɪˈfaɪn/

refine

洗練する
Meaning
to improve by making small changes; to purify
Example
The chef refines the recipe to perfection.
シェフはレシピを完璧に洗練します。
B2 verb /ˈrɛkən/

reckon

推測する
Meaning
To think, believe, or expect something; to calculate or estimate.
Example
I reckon it will rain later today.
今日は後で雨が降るだろうと思います。
B2 verb /ˈraɪpən/

ripen

幸せ
Meaning
to become or make something ready to eat or fully developed
Example
The bananas ripened quickly in the warm weather.
彼女は賞を受け取ったとき、幸せを隠せなかった。
B2 adjective /ˈrɪski/

risky

Meaning
Involving the possibility of danger, harm, or loss
Example
Investing in that startup is risky but could bring high rewards.
B2 verb /ræm/

ram

Meaning
to strike or push something with great force
Example
The truck rammed into the wall.
B2 noun /rɪˌlaɪəˈbɪləti/

reliability

信頼性
Meaning
the quality of being trustworthy or performing consistently well
Example
Customers value the reliability of our service.
お客様は私たちのサービスの信頼性を重視しています。
B2 verb /rɪˈteɪn/

retain

保持する
Meaning
to keep possession of something
Example
The company decided to retain its experienced employees.
会社は経験豊富な従業員を保持することに決めました。
B2 noun /raɪˈnɒs.ər.əs/

Rhinoceros

サイ
Meaning
a large, heavy animal with thick skin and one or two horns on its nose
Example
The rhinoceros charged through the grassland.
サイは草原を突進した。
B2 verb /rɪˈzɑlv/

resolve

解決する
Meaning
to solve a problem; to decide firmly
Example
The manager resolves the conflict between employees.
マネージャーは従業員間の対立を解決します。
B2 noun/verb /ræft/

raft

筏
Meaning
A flat structure made of logs or planks tied together, used as a boat or floating platform; to travel or transport on such a structure.
Example
They built a raft to cross the river.
彼らは川を渡るために筏を作った。
B2 adverb /ˈred.ɪ.li/

Readily

快く; 簡単に; ためらわずに
Meaning
willingly; easily; without hesitation
Example
She readily agreed to help with the project.
彼女は喜んでプロジェクトを手伝うことに同意した。
B2 noun /rɪˈstreɪnt/

Restraint

抑制; 自制
Meaning
the action of keeping someone or something under control; self-control
Example
She showed great restraint in not responding to the criticism.
彼女は批判に反応しなかったことに大きな自制心を見せた。
B2 noun /ˌreɡ.jʊˈleɪ.ʃənz/

regulations

規制
Meaning
Rules or directives made and maintained by an authority.
Example
Strict regulations ensure fair practices.
厳格な規制は公正な慣行を確保します。
B2 verb /rɪˈɡeɪn/

regain

回復する
Meaning
to get back something that was lost; to recover
Example
He regains his strength after the illness.
彼は病気の後、力を回復する。
B2 adjective /rɪˈɡret.ə.bəl/

Regrettable

残念な; 失望させる; 悲しい
Meaning
causing or deserving regret; unfortunate; deplorable
Example
It is regrettable that so many talented people left the company.
こんなに多くの才能ある人々が会社を辞めたのは残念です。