機敏|きびんkibin[0]heiban (flat)

1. na-adjective, nounquick; prompt; alert; smart; clever; astute; shrewd; quick-witted
   警察けいさつは力ちからがあって、動作どうさが機敏きびんでなければならない。↗

   A policeman should be strong and quick in action.

• Synonym敏速びんそくWrittenA rare, written-style word for quickness and agility, close to 「敏捷」; in everyday speech 「素早い」 is the natural choice.
• Synonym素早いすばやいNeutralThe everyday word for quick movement or reactions, as in 「素早く動く」; it does not highlight quick-witted adaptability the way 「機敏」 does.
• Synonym敏捷びんしょうNeutralCenters on nimble physical movement, as in 「敏捷な動き」; 「機敏」 puts more weight on quick thinking and reacting to the situation.
• Related迅速じんそくNeutralFocuses on speed of action and handling, often with matters or responses as in 「迅速な対応」; 「機敏」 stresses quick-witted adaptability instead.
• RelatedスピーディーNeutralLoanword for things moving along fast and efficiently, as in 「スピーディーな対応」; leans colloquial and stresses quick progress, not alertness.
• Related活発かっぱつNeutralLively and energetic, as in 「活発な議論」; it is about vigor and activity, and does not emphasize quick reactions.
• Related手早いてばやいNeutralQuick and deft at getting tasks done, as in 「手早く片付ける」; it is about working fast and skillfully with your hands.
• Related速やかすみやかWrittenMeans promptly, without delay, as in 「速やかに退出してください」; formal, written-flavored wording typical of notices and official documents.
• RelatedすばしっこいCasualStrongly colloquial word for nimble, quick movements — slipping away or dodging fast — said mainly of children and small animals.
• Antonym緩慢かんまんNeutralAntonym: slow movement or change, and by extension lax, ineffective handling — the opposite of the quick responsiveness of 「機敏」.
• Antonym鈍重どんじゅうNeutralAntonym: slow, sluggish movement and a dull, phlegmatic temperament — the opposite of the quick responsiveness of 「機敏」.

Use 「機敏」 for quick-witted alertness and adapting smoothly to the situation. For nimble physical movement say 「敏捷」, for fast handling of matters 「迅速」, for everyday quickness 「素早い」, and in formal notices 「速やか」. The opposites are 「鈍重」 and 「緩慢」.

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

1. 心こころの動うごきや動作どうさが、状況じょうきょうに応おうじて素早すばやいこと。