役|やくyaku[2]odaka (tail-high)

1. nounrole; assignment; responsibility; duty; function; job; service
   彼かれが重要じゅうような役やくを果はたした。↗

   He played an important part.
2. nounposition (of responsibility); post; office
3. nounpart (in a play, film, etc.); role; character
   彼かれの望のぞみはハムレットの役やくを演えんじることです。↗

   His ambition is to play the part of Hamlet.
4. noun, mahjong, card games, hanafudascoring combination; hand; yaku; meld

• Synonym役目やくめNeutralThe duty one is charged with, as in 「親の役目」; stresses the obligation one must fulfill more than 「役」 does.
• Synonym役割やくわりNeutralAn assigned role or function, as in 「重要な役割を果たす」; leans written and is the most common choice when talking about a role's function.
• Synonym任にんWrittenWritten/formal word for duty or responsibility, as in 「任に堪えない」; mostly appears in set phrases.
• Synonym役回りやくまわりCasualColloquial word for the role that falls to you, as in 「損な役回り」; often tinged with resignation.
• Synonym役柄やくがらNeutralThe character type of a role one plays or the nature of a post, as in 「悪役の役柄」.
• Synonym役儀やくぎWrittenRare written word for duty or responsibility; in everyday speech say 「役目」.
• Synonymお役目おやくめNeutralA deferential term for public duty or one's role, often carrying a solemn or tongue-in-cheek tone.
• Related任務にんむNeutralA concrete task entrusted to you, as in 「任務を果たす」; carries a sense of mission.
• Related勤めつとめNeutralOne's duty or the work of a job, as in 「親の務め」; stresses obligation more than 「役」.
• Related職務しょくむNeutralThe duties attached to one's position, as in 「職務規定」; fairly formal.
• Related仕事しごとNeutralThe broadest word for work or a job; 「役」 centers on the post or role one holds.
• Related責務せきむWrittenWritten word for the duties and obligations one must fulfill; solemn in tone.
• Related課題かだいNeutralAn issue to be solved or an assignment, as in 「今後の課題」; never refers to a role.
• Related作業さぎょうNeutralWork done step by step, as in 「作業員」; the focus is on the labor process.
• Related責任せきにんNeutralResponsibility for the results of one's actions; the emphasis is on bearing it, while 「役」 centers on the position held.
• Related業務ぎょうむNeutralProfessional business operations, as in 「業務内容」; mostly used for company work.
• Related義務ぎむNeutralWhat law or morality requires one to do; 「役」 is an assigned post or role.
• Related責めせめNeutralUsually in 「責めを負う」: the responsibility one should bear; leans written, and can also mean blame.
• RelatedタスクNeutralLoanword for a task to be done, as in 「タスク管理」; common in the workplace and on computers.
• Related職分しょくぶんWrittenWritten word for one's duty or calling; in daily speech use 「職務」 or 「役目」.
• Relatedお勤めおつとめNeutralWork or a job, or sutra reading before a Buddha statue; also marks bargain goods, as in 「お勤め品」.
• Related職掌しょくしょうWrittenRare written word for official duties or functions; in daily use say 「職務」.
• Antonym無役むやくWrittenThe opposite of 「役」 in terms of holding a post: it means having no position or assignment.

「役」 covers a post, role, or part in a play. Say 「役目」 for the duty one must fulfill, 「役割」 for a role's function, 「任務」 for an entrusted task, 「仕事」 or 「業務」 for work and business, and 「責任」 for bearing responsibility; the rest are narrower, more formal, or special-purpose terms.

Usage comparisons are AI-assisted and cross-checked by multiple models; for study reference only

1. （元々もともとの意味いみ：エキ、ヤク、えだち）古代こだい国家こっか - 近世きんせいまでの政府せいふ（官かん）から課かされる労働ろうどう。公役くやく、夫役おっとやく。
2. （転てんじて）（近代きんだい国家こっか成立せいりつ以前いぜんの政府せいふ・支配者しはいしゃが）人民じんみん・農家のうか、旅行者りょこうしゃの物品ぶっぴんに課かす税ぜい。
3. （更さらに転てんじて）辛つらい仕事しごとを与あたえる事こと。こき使つかう。
4. （ヤク　音読おんよみであるが原義げんぎにはない意味いみ）全体ぜんたいの中なかで、割り当わりあてられ受け持うけもつ仕事しごと。果はたす任務にんむ。役目やくめ・役割やくわり。（当番とうばんから名誉職めいよしょく、一定いっていの公職こうしょく・職位しょくいにまで使つかわれる。）
5. （転てんじて）もっぱらその事こと（用事ようじ）にあたること。もって任にんじる。（より軽かるい使い方つかいかた）
6. （ヤク） 責任せきにんのある、重要じゅうような職務しょくむ・地位ちい。主おもだった立場たちばの仕事しごと。（広ひろく社会的しゃかいてきな全体ぜんたいの中なかでの役やくと、組織そしきの中なかの役やくの両方りょうほうに使つかうので、語義ごぎ2との区別くべつは曖昧あいまい）
7. （ヤク）俳優はいゆう・役者やくしゃが、演えんじる人物じんぶつ・配役はいやく（なりきって演えんじる対象たいしょう）
8. （ヤク　主おもに賭け事かけごとに対たいして）賭け事かけごとのゲーム（花札はなふだ・トランプ・麻雀まーじゃん、など）で、決きまった条件じょうけんが揃そろって「勝かてる・上あがれる」状態じょうたい。上あがり役やく。
9. （ヤク・エキ）月役つきやくの略りゃく。月経げっけい。生理せいり。