How to say "mighty" in Japanese

• 強大きょうだいCommon
  na-adjective, nounCovers 'mighty' in its basic sense of powerful or strong. Use it for overwhelming power or strength — the might of a state, an army, or a ruler's authority.
  強大きょうだいな権力けんりょくを有ゆうする大国たいこくが存在そんざいする限かぎり、戦争せんそうは避さけ難がたい。↗

  As long as there are sovereign nations possessing great power, war is inevitable.
• 偉大いだいJLPT N3approx.Common
  na-adjectiveMatched to 'mighty' only loosely: it really means great, grand, or outstanding. It praises eminence — a great figure or achievement — rather than raw power, so it seldom fits the strength sense of 'mighty'.
  リンカーンは偉大いだいな政治家せいじかであった。↗

  Lincoln was a great statesman.

Choose 強大 when 'mighty' means overwhelming in power or strength; choose 偉大 when it means great or eminent — though 偉大 is really 'great', so it fits only that looser, figurative sense.

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

• 強大きょうだいpowerful
• 偉大いだいgreat
• えらいawful