How to say "uncertainty" in Japanese

• 疑いうたがいCommon
  nounCovers 'uncertainty' in the sense of doubt or skepticism about something, close to its primary meaning of doubt. Best when the uncertainty amounts to questioning or distrusting a claim, statement, or person's motives.
  それで疑うたがいをさしはさむ余地よちはなくなる。↗

  That leaves no room for doubt.
• 不定ふじょう
  noun, na-adjectiveCovers 'uncertainty' as mutability, when something is not fixed, settled, or definite, such as a date or condition that remains undetermined. A less common choice, so reserve it for this 'not fixed' sense.
• 不確実性ふかくじつせい
  nounThe most direct word for 'uncertainty' in its abstract sense: indeterminacy, unreliability, or the state of things being uncertain, as in scientific, statistical, or philosophical discussion. This is usually the word you want for that meaning.
• 疑りうたぐり
  nounA variant of 疑い with the same range of doubt, questioning, and skepticism. It is less common, so it is seldom the word you want for plain 'uncertainty'; use it mainly when you specifically mean doubt or suspicion.
• 不安心ふあんしん
  na-adjective, nounCovers 'uncertainty' tinged with emotion: uneasiness, anxiety, or apprehension about what may happen. Suits contexts where the uncertainty is felt as worry rather than reasoned doubt, though it is a less common choice.

Pick 「疑い」 for doubt or distrust, 不確実性 for abstract uncertainty or indeterminacy, 不定 for something not fixed or settled, 不安心 for anxious uneasiness, and 「疑り」 for a rarer, more literary doubt.

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

• 疑いうたがいdoubt
• 不定ふじょうuncertainty
• 不確実性ふかくじつせいuncertainty
• 疑りうたぐりdoubt
• 不安心ふあんしんuneasiness