How to say "out-of-date" in Japanese

• アウトオブデート
  na-adjective, nounA katakana borrowing of the English phrase. Despite matching 'out-of-date' exactly, it is seldom the word you want; for something behind the times, 時代遅れ is the word to use.
• 時代遅れじだいおくれ
  no-adjective, na-adjectiveCovers 'out-of-date' in the sense of old-fashioned or antiquated: literally left behind by the times, it describes people or things that lag behind what is current.
  あなたの考かんがえはまったく時代遅じだいおくれである。↗

  Your ideas are all out of date.

For 'out-of-date' meaning behind the times or old-fashioned, 「時代遅れ」 is the word to reach for; 「アウトオブデート」, a direct English loanword, is marginal and seldom the right choice.

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

• アウトオブデートout-of-date
• 時代遅れじだいおくれold-fashioned
• 古いふるいold-fashioned