How to say "eternal" in Japanese

• 不変ふへんCommon
  na-adjective, no-adjectiveCovers 'eternal' in the sense of unchanging or immutable: something that stays the same forever. Typical of truths, principles, or laws regarded as never altering.
  これ不変ふへんの真理しんりなり。↗

  This is an immutable truth.
• 悠久ゆうきゅうCommon
  no-adjective, na-adjectiveExpresses 'eternal' as vast, unbounded duration; its nuance is the grand sweep of time itself, reaching into the immemorial past, and it suits talk of history or the universe.
• 不朽ふきゅうCommon
  no-adjectiveCovers 'eternal' as immortal or enduring: it suggests something that will not decay, fade, or be forgotten. Typical of lasting works, achievements, or reputations.
  この数年間すうねんかんに彼かれは不朽ふきゅうの名詩めいしを書かいた。↗

  During these years he wrote immortal poems.

Choose 不変 when stressing that something never changes, 悠久 for the vast sweep of time itself, and 不朽 for works or achievements that endure and are not forgotten.

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

• 不変ふへんeternal
• 悠久ゆうきゅうeternal
• 不朽ふきゅうeverlasting
• エターナルeternal
• 尽きせぬつきせぬeternal
• 常磐ときわeverlasting
• 常とこconstant
• 長のながのlong
• 相も変わらぬあいもかわらぬusual
• 不朽不滅ふきゅうふめつeverlasting
• 幾久しいいくひさしいeverlasting
• 果てしがないはてしがないendless
• 悠々ゆうゆうdistant