How to say "poisonous" in Japanese

• 有毒ゆうどくCommon
  na-adjective, no-adjectiveThe straightforward word for 'poisonous': it describes things that contain poison and can harm or kill — mushrooms, plants, gases, snakes. Use it to say that something is poisonous.
  この食品しょくひんは有毒ゆうどくである。↗

  This food is unhealthy.
• 毒性どくせいCommon
  no-adjectiveReally the noun 'toxicity': it names how poisonous a substance is — its poisonous strength or virulence — rather than describing the thing itself. Seldom the word you want when simply calling something poisonous.

Use 有毒 for the plain sense 'poisonous' — describing things that contain poison; 毒性 is really the noun 'toxicity,' for discussing how poisonous a substance is rather than calling it poisonous.

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

• 有毒ゆうどくpoisonous
• 毒々しいどくどくしいpoisonous
• 毒のあるどくのあるpoisonous
• 中毒性ちゅうどくせいpoisonous
• 毒性どくせいtoxic