How to say "impulsive" in Japanese

• 無謀むぼうCommon
  na-adjective, nounCovers 'impulsive' in the sense of rash and reckless: acting without thought of the danger or consequences. Typical context: criticizing a plan or decision as foolhardy and ill-advised.
• 気まぐれきまぐれJLPT N1approx.Common
  na-adjectiveCovers 'impulsive' in the sense of whimsical and capricious: doing things on a whim, with moods or choices that change unpredictably. Typical context: a person who acts on sudden fancy rather than fixed intention.
  気きまぐれな天気てんきだな。↗

  The weather is fickle.

Choose 無謀 when 'impulsive' means rash or reckless, acting without thought of danger or consequences; choose 「気まぐれ」 when it means capricious or whimsical, acting on a whim with changeable moods.

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

• 無謀むぼうreckless
• 衝動的しょうどうてきimpulsive
• ふとしたimpulsive
• 血の気の多いちのけのおおいhot-blooded
• 血の気が多いちのけがおおいhot-blooded
• 気まぐれきまぐれcapricious