迅速|じんそくjinsoku[0]heiban (flat)

1. na-adjective, noun(very) quick; rapid; swift; speedy; prompt; expeditious
   間髪かんぱつを入いれず、迅速じんそくかつ的確てきかくな応対おうたい、畏れ入おそれいります。↗

   Such an accurate, lightning-quick reply. What can I say?

• Synonym速やかすみやかWrittenWritten and formal, common in official documents and instructions, as in 「速やかに退出」; 「迅速」 stresses speed itself — acting fast, without delay.
• SynonymスピーディーNeutralLoanword for things progressing quickly and efficiently; 「迅速」 is more formal and written in tone.
• Synonym快速かいそくNeutralMeans high speed, and also a rapid-service train; 「迅速」 is more written, for prompt, timely handling or movement.
• Synonym敏速びんそくWrittenWritten and rare; means agile quickness. In everyday speech 「迅速」 or 「素早い」 is the natural choice.
• SynonymさっさとCasualColloquial for doing something briskly, often with a note of urging; 「迅速」 is written and neutral in tone.
• Synonymいち早くいちはやくNeutralMeans acting promptly and without delay, often getting in ahead of others; 「迅速」 just says fast and does not stress beating anyone to it.
• Synonym急速きゅうそくNeutralFor rapid change or development, as in 「急速に普及」; 「迅速」 is about quick responses and actions.
• Synonym素早いすばやいNeutralAn adjective for agile movement and quick reactions; 「迅速」 is more written and covers both handling and movement.
• Synonym早いはやいNeutralThe most general word for fast or early; 「迅速」 is more written and speaks only of speed and timeliness.
• Related早々そうそうNeutralMostly as 「〜早々」, meaning 'just after …'; 「迅速」 describes speed, not the order of events in time.
• Related早くはやくNeutralMeans early or fast and often serves to urge someone on; 「迅速」 is a more written, descriptive word.
• RelatedすぐNeutralMeans 'right away' and is the most colloquial of the group; 「迅速」 is written and stresses prompt handling.
• RelatedすぐさまNeutralMeans 'at once, without a moment's hesitation'; 「迅速」 is more written, for speed with timely results.
• Related急きゅうNeutralMeans sudden or urgent; 「迅速」 says fast and timely handling but carries no sense of suddenness.
• Related急激きゅうげきNeutralDescribes changes that are sharp or abrupt; 「迅速」 is about people handling things or acting quickly.
• Related手早いてばやいNeutralMeans deft and brisk at a task — work or explanations, as 「手早く説明する」; 「迅速」 is written and just says fast.
• RelatedみるみるNeutralAn adverb for watching something change rapidly before your eyes; 「迅速」 is about quick handling or action.
• Related機敏きびんWrittenWritten, for alertness and quick-witted responses; 「迅速」 speaks only of speed, not cleverness.
• RelatedたちまちNeutralMeans something changes or happens in an instant, as 「たちまち雨が降り始めた」; 「迅速」 is about handling things fast.
• Related至急しきゅうNeutralUsed to demand urgent handling; 「迅速」 describes the speed of the work itself.
• Related早速さっそくNeutralMeans getting started on something right away, as 「早速食べてみる」; 「迅速」 is written, for speed with timeliness.
• Related手っ取り早いてっとりばやいCasualColloquial for a quick, easy way that saves effort, as 「手っ取り早い方法」; 「迅速」 focuses on speed alone.
• Related早いとこはやいとこCasualColloquial for hurrying to get something done; 「迅速」 is written in tone.
• Related早めはやめNeutralMeans a little earlier than usual, as in 「早めに出る」; 「迅速」 is about speed, not doing things early.
• RelatedキビキビCasualA colloquial mimetic word for brisk, crisp, energetic movement; 「迅速」 is more written.
• AntonymゆっくりNeutralAntonym on the fast–slow axis: doing things slowly and unhurriedly.
• Antonym遅いおそいNeutralAntonym on the fast–slow axis: slow or late.
• Antonym緩慢かんまんWrittenWritten antonym on the fast–slow axis: movement or progress that is sluggish and slow.

Use 「迅速」 for quick, timely handling, responses or movement — 「迅速な対応」「迅速に移動する」 — with a written, formal flavour. For official notices asking prompt action, prefer 「速やかに」. In everyday speech say 「すぐ」 or 「早い」. For agile movement or reactions use 「素早い」; for rapid change or development 「急速」. 「早々」「早め」「いち早く」「忽ち」 add time nuances — just after, earlier, first, in an instant — that 「迅速」 lacks; 「さっさと」 and 「早いとこ」 are colloquial. The opposites are 「緩慢」 and 「遅い」.

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

1. 動うごきが速はやいこと。