How to say "trigger" in Japanese

• トリガーCommon
  nounThe loanword, covering the same ground as English 'trigger': the part that sets off a mechanism, and figuratively the stimulus that sets off an event, reaction, or response.
• 引き金ひきがねCommon
  nounThe trigger of a gun, literally the lever pulled to fire it; figuratively, the direct act or factor that sets off an incident or chain of events.
  その男おとこはピストルを額がくにあて、引き金ひきがねを引ひいた。↗

  The man put the gun against his forehead and squeezed the trigger.
• 契機けいきJLPT N1approx.Common
  nounAn event that serves as the occasion or impetus for a change or new development; it presents the trigger as something a shift hinges on, not a physical mechanism.
• 火種ひだねCommon
  nounLiterally embers kept alight; used for a lingering source of trouble that could flare into disturbance or conflict, such as a dispute that remains a flashpoint.
• 口火くちびCommon
  nounLiterally the first flame; the spark that opens a war, argument, or revolt, stressing the opening moment when hostilities or a dispute actually begin.

Use 「トリガー」 as the all-purpose loanword (technical and figurative), 「引き金」 for a gun's trigger and direct causes, 契機 for events prompting change, and 火種 or 口火 for conflicts—smoldering potential versus the opening spark.

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

• トリガーtrigger
• 引き金ひきがねtrigger (of a gun, etc.)
• 契機けいきtrigger
• 火種ひだねcause (of disturbance, conflict, etc.)
• 口火くちびcause (of a war, argument, revolt, etc.)
• 起こすおこすto cause
• 地雷じらいtopic that sets someone off
• 誘い水さそいみずcause
• 起爆剤きばくざいtrigger