How to say "presumption" in Japanese

• 推定すいていJLPT N2approx.Common
  suru verb, transitive verb, no-adjectiveCovers presumption in the sense of an assumption or provisional conclusion: taking something to be the case without direct proof. This is the common word for that sense, especially in legal and official contexts.
  彼かれの死しは事故じこだとする君きみの推定すいていは間違まちがっているようだ。↗

  Your assumption that his death was an accident seems to be wrong.
• 推認すいにん
  noun, suru verb, transitive verbCovers presumption as inference: concluding that something is likely from the evidence at hand. It is less common than 推定 and stresses the reasoning by which the conclusion is reached.
• 烏滸の沙汰おこのさた
  nounCovers presumption as impertinence: behavior so presumptuous or absurd that it defies common sense. A set phrase for a foolish or insolent act, so it fits only this behavioral sense, never the assumption sense.
• 盲進もうしん
  noun, suru verb, intransitive verbReally means rushing recklessly ahead without looking; 'presumption' here is only the sense of headlong, overbold action. Seldom the word you want when translating 'presumption'.
• 思い上がりおもいあがり
  nounCovers presumption as arrogance: the attitude of people who overestimate themselves and act presumptuously. Choose this when 'presumption' criticizes someone's conceit rather than an assumption or an inference.

Use 推定 for presumption as an assumption or inference, 推認 for conclusions drawn from evidence, 「思い上がり」 for arrogant self-importance, 「烏滸の沙汰」 for impertinent behavior, and 盲進 for reckless headlong action.

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

• 推定すいていpresumption
• 推認すいにんpresumption
• 烏滸の沙汰おこのさたstupidity
• 盲進もうしんrushing recklessly
• 思い上がりおもいあがりconceit