キーkii

1. nounkey (for a lock)
   彼女かのじょはキーを探さがしてポケットをさぐった。↗

   She searched her pockets for the key.
2. nounkey (of a piano, organ, computer keyboard, etc.)
   彼女かのじょはピアノのキーを押おした。↗

   She depressed the keys of the piano.
3. noun, musickey
4. nounkey (to solving something); clue
5. prenominal modifierkey (person, point, etc.); most important

• Synonym鍵かぎNeutralA physical key or a lock, also used figuratively as in 「成功の鍵」; 「キー」 additionally covers keyboard and piano keys.
• SynonymキーポイントNeutralA loanword for the key point needed to understand or solve something; close to 「キー」 in its key sense, with more stress on the essential point.
• Synonym手がかりてがかりNeutralA clue for solving a problem or cracking a case, or a place to grip with the hand; 「キー」 is the key that decides success or failure.
• Related足がかりあしがかりNeutralA foothold for climbing, or a stepping stone for moving forward, as in 「進出の足がかり」; 「キー」 is the key to solving a problem.
• RelatedきっかけNeutralThe trigger or occasion that gets something started, as in 「話のきっかけ」; 「キー」 is the key element that decides the outcome.
• Related示唆しさWrittenAn indirect hint or suggestion that inspires, as in 「示唆に富む」; written/formal prose. 「キー」 is the key itself, not a hint.
• Related端緒たんしょWrittenThe beginning or first thread of something, as in 「解決の端緒」; written/formal prose. 「キー」 is about the key, not the start.
• Related秘訣ひけつNeutralA secret trick or know-how that others don't know, as in 「上達の秘訣」; 「キー」 points to the key, which need not be a secret.
• Related決め手きめてNeutralThe factor or clinching evidence that decides a contest or a question of truth, or the person who decides; 「キー」 is a key in the broad sense.
• Related暗示あんじNeutralSuggesting something without saying it outright; also psychological suggestion. 「キー」 is the key itself, not a way of conveying it.
• RelatedヒントNeutralA loanword for a hint or clue, given by someone or gained from observation or experience, as in 「経験からヒントを得る」; 「キー」 is the key itself.
• Related手蔓てづるNeutralConnections or pull you can rely on — the emphasis is on personal networks; 「キー」 is the key element in solving a problem.
• RelatedほのめかしNeutralLetting your intentions show indirectly, without saying them outright; not often used. 「キー」 is the key element itself.
• Related要訣ようけつWrittenThe most important point of something; written and rare — in everyday speech use 「コツ」 or 「秘訣」.
• Related要諦ようていWrittenThe single most important point, as in 「要諦を押さえる」; written/formal prose, while 「キー」 is more colloquial.

Use 「キー」 for a physical key or a keyboard or piano key. For a figurative key 「鍵」 also works; use 「手がかり」 for clues, 「秘訣」 for secret know-how, 「決め手」 for the deciding factor, and 「ヒント」 for hints. The rest are narrower: triggers and starting points (「切っ掛け」, 「足がかり」, 「端緒」), indirect hints (「暗示」, 「示唆」, 「仄めかし」), and words for the essential point (「キーポイント」, 「要諦」, 「要訣」).

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

1. かぎ。
2. 問題もんだいを解決かいけつするために役立やくだつ手てがかり。
3. 鍵盤けんばん楽器がっきで音おとを鳴ならすために指ゆびで押おす部分ぶぶん。鍵かぎ。
4. 管楽器かんがっきで、鳴なる音おとの高たかさを変かえるための穴あなを開閉かいへいするために指ゆびで押おす部分ぶぶん。
5. コンピューターやタイプライターで文字もじを入力にゅうりょくしたり操作そうさしたりするために指ゆびで押おすボタンで、盤ばんに並ならんだものの一ひとつ一ひとつ。
6. 調ちょう。
7. コンピューターで、データの検索けんさく、並べ替ならべかえなどに使用しようする項目こうもく。
8. 軸じくと穴あなをまたいで付つけられ、軸じくと穴あなの間あいだでトルクを伝つたえる部品ぶひん。