radix
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 英語 BN ベンガル語 HI ヒンディー語 ES スペイン語 FR フランス語 DE ドイツ語 RU ロシア語 ZH 中国語 JA 日本語
All Vocabulary Cards All Vocabularies
C2 noun /ˈreɪdɪks/

radix

基数
Meaning
the base or root of something; the number on which a system of numeration is built
Example
In mathematics, the decimal system has a radix of ten.
数学では、十進法の基数は十です。
B2 adverb /ˈræp.ɪd.li/

Rapidly

速やかに; 急速に
Meaning
at a fast speed; quickly
Example
The company is rapidly expanding into new markets.
会社は新しい市場に急速に拡大しています。
C1 adjective /rɪˈsɜːrdʒənt/

resurgent

復活した
Meaning
Becoming strong, active, or popular again.
Example
The resurgent economy gave hope to many businesses.
復活した経済は多くのビジネスに希望を与えた。
C2 noun /ˌræʃioʊsɪˈneɪʃən/

ratiocination

推論
Meaning
the process of reasoning or logical thinking
Example
His ratiocination impressed the judges during the debate.
彼の推論は討論中に審査員を感動させた。
C1 verb /rɪˈkaʊnt/

recount

語る
Meaning
to narrate or tell the details of an event or experience
Example
She recounted her adventures during the summer trip.
彼女は夏の旅行中の冒険について語った。
A1 adjective /ˈrɛd.i/

ready

準備ができた
Meaning
Prepared or available for use or action.
Example
She was ready to leave for the airport.
彼女は空港に行く準備ができていた。
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。
A1 verb /raɪd/

ride

乗る/ライディング
Meaning
to travel on or in a vehicle; to sit on and control a horse
Example
She likes to ride her bicycle to work.
彼女は自転車で仕事に行くのが好きです。
B2 verb /rɪˈvoʊlt/

revolt

反乱する
Meaning
to rebel against authority; to feel disgust
Example
The people revolted against the corrupt government.
人々は腐敗した政府に反乱を起こしました。
B2 verb /reɪd/

raid

踏み込む
Meaning
to attack suddenly; to search and seize
Example
Police raid the illegal gambling house.
警察は違法なギャンブルの家に踏み込む。
C1 verb /rɪɡ/

rig

操作する
Meaning
to manipulate or control something dishonestly; to set up equipment
Example
The election was rigged by corrupt officials.
選挙は腐敗した役人によって操作されました。
C2 adjective /rɪˈfʌldʒənt/

refulgent

輝く
Meaning
Shining brightly; radiant.
Example
The refulgent sun lit up the entire valley.
輝く太陽が谷全体を照らした。
C1 noun /ˈrɪdəns/

riddance

解放
Meaning
The action of getting rid of something unwanted or unpleasant.
Example
His departure was considered a welcome riddance by the team.
彼の退職はチームにとって歓迎すべき解放と見なされた。
C1 noun/verb /rɪˈlæps/

relapse

再発
Meaning
to return to a worse condition, especially after improvement; a deterioration after recovery
Example
After months of progress, he suffered a relapse.
数ヶ月の進歩の後、彼は再発しました。
C2 verb /rɛnd/

rend

引き裂く
Meaning
to tear something apart violently or forcefully
Example
The explosion rent the air with a deafening noise.
爆発は耳をつんざくような音で空気を引き裂いた。
C1 noun /ˈrep.lɪ.kə/

Replica

レプリカ
Meaning
an exact copy or model of something, especially one on a smaller scale
Example
The museum displayed a perfect replica of the ancient statue.
博物館は古代の彫像の完璧なレプリカを展示しました。
B1 noun /rɪˈpleɪsmənt/

replacement

交換
Meaning
the act of substituting one thing or person for another
Example
She got a replacement for her damaged phone.
彼女は壊れた電話の交換を受けました。
B2 verb /rɪˈzɛnt/

resent

恨む
Meaning
to feel bitterness or displeasure about something or someone
Example
She began to resent the constant criticism from her boss.
彼女は上司からの絶え間ない批判をリゼントし始めました。
C1 noun/verb /rɪˈpriːz/

reprise

繰り返し
Meaning
A repetition or return to an earlier theme, role, or action.
Example
The actor reprised his role in the sequel.
俳優は続編で自分の役を再演しました。
B2 noun /reɪk/

Rake

レーキ
Meaning
a garden tool with a long handle and prongs for gathering leaves; to gather with a rake
Example
He used a rake to gather the fallen autumn leaves.
彼は落ち葉を集めるためにレーキを使いました。
C1 noun /ˈrɛz.ə.nəns/

resonance

共鳴
Meaning
A deep, reverberating sound or a quality of evoking response.
Example
His speech had a deep resonance with the audience.
彼のスピーチは観客に深い共鳴を与えた。
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。
B1 verb /rɪˈleɪt/

relate

関連する
Meaning
to connect or show a link between; to tell a story
Example
She relates her experience to the audience.
彼女は観客に自分の経験を話します。
B2 adjective rəʊˈbʌst

robust

ロバスト
Meaning
Strong and healthy; vigorous; able to withstand or overcome adverse conditions.
Example
The robust infrastructure ensures reliable communication.
ロバストなインフラは信頼できる通信を保証します。
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。
C2 noun /red ˌəʊ.liˈæn.dər/

Red oleander

赤いオリンダー
Meaning
a poisonous flowering shrub with bright red or pink flowers
Example
The red oleander blooms throughout the summer months.
赤いオリンダーは夏の数ヶ月間咲きます。
C1 noun ˈrez.ɪ.djuːz

residues

残留物
Meaning
A small amount of something that remains after the main part has gone or been taken or used.
Example
The burning process leaves no harmful residues.
燃焼プロセスでは有害な残留物は残りません。
C2 adjective /ˈrɛkənˌdaɪt/ or /ˈrɛkəndaɪt/

recondite

ほとんど知られていない、または理解しにくい
Meaning
Little known or difficult to understand.
Example
The professor’s lecture was full of recondite theories.
教授の講義は難解な理論で満ちていた。
B2 adjective /ˈrʌs.ti/

Rusty

錆びた; 練習不足; 最近の練習不足による障害
Meaning
affected by rust; out of practice; impaired by lack of recent practice
Example
My piano skills are rusty after not playing for years.
何年もピアノを弾いていなかったので、私のピアノのスキルは錆びついています。
C1 noun ˌriːˈstrʌk.tʃər.ɪŋ

restructuring

再構築
Meaning
The action of organizing something differently.
Example
The company underwent restructuring to improve efficiency.
会社は効率を高めるために再構築を行った。
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 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。
C2 adjective /rəˈʃɛrʃ/

recherche

希少
Meaning
Rare, exotic, or obscure, often in a sophisticated or refined way.
Example
The gallery displayed many recherche artworks from unknown artists.
ギャラリーは、未知のアーティストによる多くの希少なアート作品を展示しました。
C1 noun /rɪˈmɛmbrəns/

remembrance

記憶
Meaning
the act of remembering or honoring someone or something
Example
A service was held in remembrance of the fallen soldiers.
戦死した兵士たちを記憶するための式典が行われた。
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 noun /ræk/

Rack

ラック
Meaning
a framework or structure for holding or storing things
Example
She hung her coat on the rack by the door.
彼女はドアの横のラックにコートを掛けた。
B2 adverb /ˈraɪtli/

Rightly

正しく; 適切に; 公正に
Meaning
correctly; properly; justly
Example
She rightly pointed out the mistakes in the report.
彼女は報告書の誤りを正しく指摘した。
C2 adjective /ˈruːmi/

rheumy

涙目
Meaning
Watery, especially referring to the eyes.
Example
His rheumy eyes showed signs of age and fatigue.
彼の涙目は年齢と疲れの兆しを示していた。
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。
B1 noun, verb /ˈrɒkɪt/

rocket

幸せ
Meaning
a missile or vehicle propelled by a rocket engine; to increase or move very quickly
Example
The company’s profits rocketed after the new product launch.
彼女は賞を受け取ったとき、幸せを隠せませんでした。
C2 verb /ˈrævəl/

ravel

絡まる / 解く
Meaning
to tangle or complicate; to untangle or unravel depending on context
Example
She began to ravel the loose threads of the sweater.
彼女はセーターのゆるい糸をほどき始めました。
B1 noun raɪts

rights

権利
Meaning
A moral or legal entitlement to have or obtain something or to act in a certain way.
Example
The rights of people were prioritized.
人々の権利は優先されました。
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。
C1 noun /ˌrev.əˈluː.ʃən.ər.i ˈbreɪk.θruː/

revolutionary breakthrough

革命的な発見
Meaning
A sudden, dramatic, and important discovery or development that changes everything.
Example
Robotic surgery is a revolutionary breakthrough in healthcare.
ロボット手術は医療分野での革命的な発見です。
C1 noun, adjective /ˈrɛvərənd/

reverend

牧師, 尊敬される
Meaning
A title of respect used for members of the clergy; deserving deep respect.
Example
The Reverend gave an inspiring sermon at the church.
レヴァレンドは教会で感動的な説教をしました。
B1 noun rɪˈzɪs.təns

resistance

抵抗
Meaning
The refusal to accept or comply with something; the attempt to prevent something by action or argument.
Example
The resistance fought bravely against colonial forces.
レジスタンスは植民地軍に勇敢に立ち向かいました。
C1 noun /riˈæktənt/

reactant

Meaning
A substance that takes part in and undergoes change during a chemical reaction.
Example
Oxygen is a reactant in the process of combustion.
B2 adjective /rɪˈspek.tɪv/

Respective

それぞれの; 各自の
Meaning
belonging to each individual; particular to each
Example
The students returned to their respective classrooms after lunch.
学生たちは昼食後、それぞれの教室に戻った。
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 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。
C1 noun /rɪˈpɑːzɪtɔːri/

repository

リポジトリ
Meaning
a place where things are stored or kept for safekeeping
Example
The library serves as a repository of knowledge.
図書館は知識のリポジトリとして機能します。
C1 verb /reɪv/

rave

絶賛する
Meaning
to speak or write about something with great enthusiasm or admiration
Example
Critics rave about the new movie.
批評家たちは新しい映画を絶賛しています。
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。
A1 noun /roʊd/

road

道路
Meaning
a wide way leading from one place to another
Example
We drove along the road to the village.
私たちは村に向かってその道路を運転していました。
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, 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。
C1 noun /ˌrɛtrɪˈbjuːʃən/

retribution

報復, 罰
Meaning
punishment inflicted as vengeance for a wrong or crime
Example
The villagers demanded retribution for the crime committed.
村人たちは犯された犯罪に対して報復を要求しました。
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 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。
A2 verb /riːtʃ/

reach

到達する
Meaning
to arrive at a destination; to extend one's arm to touch something
Example
We will reach the station in ten minutes.
私たちは10分以内に駅に到着します。
C1 adjective /ˈræb.ɪd/

rabid

狂信的
Meaning
Having extreme or fanatical support for something; relating to or suffering from rabies.
Example
He was a rabid fan of the football team.
彼はサッカーチームの狂信的なファンだった。
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。
A2 noun /ruːl/

rule

規則
Meaning
an accepted principle or instruction that states what is allowed or what must be done.
Example
There are strict rules about safety in the lab.
実験室には安全に関する厳しい規則があります。
B1 noun /rɪˈɡret/

Regret

後悔
Meaning
a feeling of sadness or disappointment about something that has happened or been done
Example
She felt deep regret about her harsh words.
彼女は自分の辛辣な言葉に深い後悔を感じていました。
C1 adjective /ˈrɪkɪti/

rickety

ぐらつく
Meaning
Poorly made and likely to collapse; shaky.
Example
They crossed a rickety wooden bridge over the river.
彼らは川を越える不安定な木製の橋を渡りました。
A1 noun /ruːm/

room

部屋
Meaning
A space within a building enclosed by walls, floor, and ceiling
Example
She decorated her room with bright colors.
彼女は明るい色で自分の部屋を飾りました。
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。
B1 adjective /rʌf/

Rough

ざらざらした; 荒い; 厳しい
Meaning
having an uneven surface; not smooth; harsh
Example
The rough surface of the rock hurt my hands.
岩石のざらざらした表面が私の手を傷つけました。
A2 verb /rɪˈmuːv/

remove

削除する
Meaning
to take something away; to eliminate or delete
Example
Please remove your shoes before entering the house.
家に入る前に靴を脱いでください。
C1 verb rɪˈlɪŋ.kwɪʃ

relinquish

放棄する
Meaning
To give up any authority, responsibility, or property.
Example
He decided to relinquish his position as CEO.
彼はCEOのポジションを放棄することに決めました。
B1 verb /rɪd/

rid

取り除く
Meaning
to remove or get rid of something
Example
I need to rid the house of all the clutter.
家の中のすべてのゴミを取り除く必要があります。
C2 adjective /rəˈpeɪ.ʃəs/

rapacious

貪欲
Meaning
having an extreme desire to take things for oneself, greedy
Example
The rapacious landlord raised the rent without reason.
貪欲な家主は理由もなく家賃を上げた。
C1 noun /ˈreɪ.vən/

Raven

ワタリガラス
Meaning
a large, black bird with a thick bill and harsh croaking voice
Example
The raven perched on the old oak tree and cawed loudly.
ワタリガラスが古いオークの木に止まり、大きな声で鳴いた。
C1 noun /rɪˈkɜr.əns/

Recurrence

再発
Meaning
the fact of something happening again; an instance of something happening again
Example
The doctor was concerned about the recurrence of the patient's symptoms.
医師は患者の症状の再発について懸念していました。
C1 noun /rɪˈvɜːrʒən/

reversion

逆転
Meaning
the act of returning to a previous state or condition
Example
The new policy marked a reversion to traditional methods.
新しい政策は伝統的な方法への逆転を意味しました。
B2 adjective /rɪˈfreʃ.ɪŋ/

Refreshing

さわやか
Meaning
making one feel energized and renewed; pleasantly new or different
Example
The cool breeze was refreshing after the hot day.
暑い一日後の涼しい風はさわやかだった。
C1 adjective ˈriːdʒən spəˈsɪfɪk

region-specific

地域特有
Meaning
Relating to or characteristic of a particular region or area.
Example
Climate change impacts are region-specific.
気候変動の影響は地域特有です。
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。
A2 noun /ˈriː.zənz/

reasons

理由
Meaning
Causes, explanations, or justifications for an action or event.
Example
Reasons for pollution need addressing urgently.
汚染の理由は緊急に対処する必要があります。
C1 adjective /rɪˈzɪstɪv/

resistive

抵抗性
Meaning
tending to resist or oppose; in physics, relating to electrical resistance
Example
The material has resistive properties that slow down current flow.
その材料は、電流の流れを遅くする抵抗性の特性を持っています。
C1 verb /ˌriːˈkæst/

recast

再キャスティング
Meaning
To present or change something in a different form or style.
Example
The director decided to recast the role with a younger actor.
監督は役を若い俳優でリキャストすることに決めました。
B2 verb /rɪˈzɛmbəl/

resemble

似ている
Meaning
to look like or be similar to something or someone
Example
She resembles her mother in both appearance and mannerisms.
彼女は見た目と仕草の両方で母親に似ています。
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。
C1 verb /ˈræʃənəlaɪz/

rationalize

合理化する
Meaning
to attempt to explain or justify behavior or decisions with logical reasons, even if they are not true or appropriate
Example
She tried to rationalize her lateness by blaming the traffic.
彼女は交通渋滞を責めて、遅刻を合理化しようとした。
B2 verb /riːp/

reap

収穫する
Meaning
to cut or gather a crop; to receive as a consequence of actions
Example
Farmers reap wheat in the late summer.
農家は晩夏に小麦を収穫します。
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 /rɪp/

rip

裂ける
Meaning
to tear something quickly or violently
Example
He accidentally ripped his shirt on the fence.
彼はフェンスでシャツをうっかり裂けてしまいました。
C2 noun /ˈrɪɡməˌroʊl/

rigmarole

面倒なこと
Meaning
a long, complicated, and confusing process or story
Example
Getting a visa was such a rigmarole of paperwork and interviews.
ビザを取得するのは、書類とインタビューの面倒なことだった。
B2 noun /ˈrɪdəl/

Riddle

謎
Meaning
a question or statement intentionally phrased so as to require ingenuity in ascertaining its answer or meaning; a puzzle
Example
The ancient riddle stumped all the scholars for years.
その古代の謎は何年もの間、すべての学者を困らせました。
C2 verb /raɪv/

rive

裂ける
Meaning
to tear apart violently
Example
The earthquake rived the ground in several places.
地震がいくつかの場所で地面を裂けました。
C1 verb /rɪˈsɜːrdʒ/

resurge

再興
Meaning
To rise, increase, or become active again after a decline.
Example
Interest in traditional crafts has begun to resurge.
伝統工芸に対する関心が再び高まり始めています。
A2 noun reɪndʒ

range

範囲
Meaning
The extent or scope of something; the distance that can be covered or the limits within which something operates.
Example
The new electric car has a range of 400 miles.
新しい電気自動車の範囲は400マイルです。
C1 verb /ˈræʃənaɪz/

rationlize

合理化する
Meaning
to justify or explain something with logical reasons, even if not appropriate or true
Example
He tried to rationlize his mistake by blaming the system.
彼はシステムを責めて自分のミスを合理化しようとした。
C1 noun /rʌsk/

Rusk

乾燥ビスケット; トーストパン
Meaning
a hard, dry biscuit or twice-baked bread; a type of crisp, sweet biscuit
Example
The baby enjoyed eating the soft rusk with milk.
赤ちゃんはミルクと一緒に柔らかいラスクを食べるのが好きでした。
B1 adjective /rɪˈleɪ.tɪd/

Related

関連; 結びついている
Meaning
connected; associated; having a connection or relationship
Example
These two problems are closely related to each other.
これらの二つの問題はお互いに密接に関連しています。
C2 noun /ˈrɪvjʊlət/

rivulet

小川
Meaning
a small stream of water; a tiny brook
Example
A rivulet ran down the hillside after the rain.
雨の後、小川が丘を下った。
C1 verb /rɪˈkuːpəreɪt/

recuperate

回復する
Meaning
to recover from illness or regain strength
Example
She went to the countryside to recuperate after surgery.
彼女は手術後、回復するために田舎に行った。
C2 noun /ˈræp.aɪn/

rapine

略奪
Meaning
the violent seizure of someone's property
Example
The war was marked by rapine and destruction.
戦争は略奪と破壊で特徴づけられていた。
C1 verb /rɪˈsʌsɪteɪt/

resuscitate

Meaning
to revive someone from unconsciousness or apparent death
Example
The doctors tried to resuscitate the patient after the heart attack.
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。
C1 verb /riːˈfɜːrbɪʃ/

refurbish

改装する
Meaning
To renovate or redecorate something, especially a building.
Example
The company decided to refurbish its old office.
その会社は古いオフィスを改装することを決定しました。
C1 noun /rɪˈspɒnsɪvnəs/

responsiveness

反応性
Meaning
The quality of reacting quickly and positively
Example
The manager appreciated her responsiveness to customer feedback.
マネージャーは彼女の顧客からのフィードバックに対する反応性を評価しました。
C1 noun ˌræʃ.ən.əl.ɪˈzeɪ.ʃən

rationalization

合理化
Meaning
The practice of finding reasons for behavior or actions that are not the real reasons.
Example
His rationalization of the mistake was not convincing.
彼の間違いの合理化は説得力がなかった。
B2 adjective /ˈrɪdʒ.ɪd/

Rigid

硬直
Meaning
hard and stiff; not able to bend; strict and unwilling to change
Example
The company has a rigid dress code that all employees must follow.
会社にはすべての従業員が従う必要がある厳格なドレスコードがあります。
B1 noun rɪˈsɜː.tʃəz

researchers

研究者
Meaning
People who study and investigate to discover new information or facts.
Example
Researchers are working on innovative solutions.
研究者たちは革新的な解決策に取り組んでいます。
A2 noun /ˈruːlər/

ruler

支配者; 定規
Meaning
A person who governs or controls a country; a straight-edged tool used for measuring or drawing lines
Example
The ruler drew a straight line on the paper while the king was a powerful ruler of his kingdom.
ルーラーは紙にまっすぐな線を引き、王は自分の王国の強力な支配者でした。
C1 adjective /ˈrʌs.tɪk/

Rustic

シンプルで洗練されていない; 農村地域に関連
Meaning
simple and unsophisticated; relating to rural areas
Example
The rustic cottage had wooden beams and a thatched roof.
そのラスティックな小屋は木製の梁と藁葺きの屋根を持っていた。
C2 noun /rɪˈpoʊst/

riposte

鋭い返答
Meaning
a quick and clever reply to criticism or an insult
Example
Her sharp riposte left everyone in silence.
彼女の鋭い返答は皆を黙らせた。
B2 noun /rɪˈmeɪn.dər/

Remainder

残り; 余り
Meaning
the part that is left over; what remains after the other parts have been taken away
Example
The remainder of the food was stored in the refrigerator.
残りの食べ物は冷蔵庫に保存されました。
C2 verb /rɪˈpruːv/

reprove

叱る
Meaning
to criticize or correct someone gently or disapprove of their actions
Example
The teacher reproved the student for being late.
先生は遅刻した生徒を叱りました。
C2 noun /rɪˈfɛktəri/

refectory

食堂
Meaning
a dining hall, especially in a monastery, convent, or school
Example
Students had lunch in the refectory.
学生たちは食堂で昼食をとった。
C1 noun rɪˌkuːpərˈeɪʃən

recuperation

回復
Meaning
The process of gradually recovering from illness or fatigue
Example
Rest is essential for recuperation after illness.
病気からの回復には休息が不可欠です。
C2 noun /ruːd/

rood

十字架
Meaning
a crucifix, especially one positioned above the entrance to the chancel of a church
Example
The old church displayed a carved rood above the altar.
古い教会は祭壇の上に彫られた十字架を展示していました。
C2 noun /ˈriːbəs/

rebus

なぞなぞ
Meaning
a puzzle in which words are represented by pictures, symbols, or letters
Example
The children enjoyed solving the rebus puzzles in the magazine.
子供たちは雑誌のなぞなぞを解くのを楽しみました。
C1 noun /ˈroʊz ˈwɔː.tər/

Rose-water

ローズウォーター
Meaning
a flavored water made by steeping rose petals in water, used in cooking and cosmetics
Example
She added a few drops of rose-water to the dessert.
彼女はデザートにローズウォーターを数滴加えました。
C1 noun /ˈrɛvərəns/

reverence

尊敬
Meaning
deep respect for someone or something
Example
The students showed reverence to their teacher.
学生たちは先生に尊敬を示した。
C1 adjective /rɪˈvenʒ.fəl/

Revengeful

復讐心に燃える
Meaning
seeking or desiring revenge; vindictive
Example
He became revengeful after being betrayed by his friend.
彼は友達に裏切られた後、復讐心に燃えるようになった。
B1 adjective rɪˈlaɪ.ə.bəl

reliable

信頼できる
Meaning
Consistently good in quality or performance; able to be trusted.
Example
Reliable systems ensure efficiency.
信頼できるシステムは効率を確保します。
C1 noun ˈremnənts

remnants

遺物
Meaning
A small remaining quantity of something; a surviving trace.
Example
The remnants of the wall are still visible.
壁の遺物はまだ見える。
B2 adverb /rɪˈspektɪvli/

Respectively

それぞれ; 指定された順序で; 別々に、そしてすでに言及された順序で
Meaning
in the order given; separately and in the order already mentioned
Example
John and Mary are 25 and 30 years old respectively.
ジョンとメアリーはそれぞれ25歳と30歳です。
C2 adjective /rɪˈkʌmbənt/

recumbent

横たわる
Meaning
lying down or in a resting position
Example
He was found recumbent on the sofa after a long day.
彼は長い一日の後、ソファで横になっているのが見つかりました。