How to say "short-lived" in Japanese

• はかないJLPT N1approx.Common
  i-adjectiveCovers the fleeting, transient sense of short-lived: something that vanishes quickly, often with a poignant, wistful feel, as with beauty, emotions, or life itself. Usually written in kana alone.
  人生じんせいは儚はかないよ、と人ひとは言ゆう。↗

  People say that life is short.
• 一時的いちじてきCommon
  na-adjectiveCovers the plainly temporary sense: a state or condition that lasts only a short while and then ends or reverts, such as a temporary measure or a short-lived improvement. Matter-of-fact rather than poignant.
  彼かれは一時的いちじてきに精神せいしんが錯乱さくらん状態じょうたいになった。↗

  He became temporarily deranged.

Choose 「はかない」 for the fleeting, poignant sense of things that vanish almost as soon as they appear, and 一時的 for conditions that are merely temporary, lasting a short time before ending or reverting.

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

• はかないfleeting
• 一時的いちじてきtemporary