How to say "astounding" in Japanese

• 驚天動地きょうてんどうち
  no-adjectiveCovers the 'world-shaking' sense: news or events so momentous they seem to shake heaven and earth. A set four-character idiom and less common, it fits dramatic descriptions of such happenings.
• 突拍子もないとっぴょうしもない
  expression, i-adjectiveMatches the 'wild, crazy' sense: an astounding idea, plan or remark in the sense of wildly off the wall. Less common, and closer to 'outrageous' or 'preposterous' than to 'amazing'.
  トムと飲のみに行いくんだったら、突拍子とっぴょうしもないホラを吹ふくだろうから、覚悟かくごした方ほうがいいよ。↗

  If you go drinking with Tom, be prepared to listen to some pretty outlandish cock and bull stories.
• 驚異的きょういてき
  na-adjectiveThis is the positive, 'marvellous' sense: astounding as in a wonderful result or achievement. Use it when you mean 'amazingly impressive' rather than shocking or wild.
  彼かれは驚異的きょういてきな力ちからで自動車じどうしゃを持ち上もちあげた。↗

  He lifted the car with his phenomenal strength.
• 衝撃的しょうげきてき
  na-adjectiveFor 'astounding' in the negative sense of shocking or devastating: news so upsetting it leaves you stunned. Seldom the word for the 'amazing' sense — it is really 'shocking', not 'wonderful'.
• 恐るべきおそるべきCommon
  prenominal modifierCovers the 'staggering' sense: astounding on a scale that inspires awe or dread — tremendous ability, force or achievement. A common word, and the one to reach for when 'formidable' fits the English.

Choose by flavour: 驚異的 for marvellous achievement, 「恐るべき」 for staggering, awe-inspiring scale, 「突拍子もない」 for wildly outrageous ideas, 衝撃的 for shocking news, and 驚天動地 for world-shaking events.

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

• 驚天動地きょうてんどうちastounding
• 突拍子もないとっぴょうしもないastounding
• 驚異的きょういてきwonderful
• 衝撃的しょうげきてきdevastating
• 恐るべきおそるべきastonishing