不確実|ふかくじつfukakujitsu

1. na-adjective, noununcertain; unreliable; inauthentic; insecure
   ネット上じょうの不ふ確実かくじつな情報じょうほうを鵜呑うのみにしてはならない。↗

   You mustn't swallow unreliable information that's on the Web.

• Synonym不確定ふかくていWrittenWritten noun for what is not yet determined, as in 「不確定要素」; focuses on the outcome still being undecided.
• Synonym不確かふたしかNeutralNa-adjective for something inexact or unreliable, as in 「記憶が不確か」; common in speech.
• SynonymあやふやNeutralNa-adjective for vague, ambiguous matters, as in 「あやふやな返事」; colloquial, stressing a noncommittal attitude.
• Related曖昧あいまいNeutralNa-adjective for vague, unclear wording, as in 「曖昧な表現」; stresses that the expression itself is muddled.
• Related未定みていNeutralNoun for what has not been decided yet, as in 「日程未定」; stresses that the decision is still pending.
• Related不定ふていWrittenWritten noun for what is not fixed, as in 「住所不定」; stresses that things keep shifting or varying.
• Related半信半疑はんしんはんぎNeutralFour-character idiom for half believing and half doubting; stresses one's inner doubt about something.
• RelatedおぼつかないNeutralI-adjective for lacking confidence or for unsteady steps, as in 「足元が覚束ない」.
• Related宙ぶらりんちゅうぶらりんCasualColloquial noun for something left hanging undecided, as in 「宙ぶらりんの状態」; stresses the suspended, up-in-the-air state.
• Related不明瞭ふめいりょうWrittenWritten na-adjective for what is unclear or indistinct, as in 「不明瞭な説明」; leans toward formal prose.
• RelatedおぼろげNeutralNa-adjective for hazy, faint impressions, as in 「おぼろげな記憶」; stresses dimness, especially of memories.
• Related心もとないこころもとないNeutralI-adjective for feeling insecure and anxious, as in 「心もとない」; stresses the worry itself.
• Antonym確実かくじつNeutralAntonym: na-adjective for what is certain and reliable; the direct opposite of 「不確実」.

Use 「不確実」 when prospects or outcomes are uncertain or unreliable, as in 「不確実な時代」. For what is not yet determined use 「不確定」 or 「未定」; for imprecise memories 「不確か」; for vagueness 「あやふや」 or 「曖昧」. For certainty, choose 「確実」.

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

1. 確実かくじつでないこと。はっきりしないさま。不確ふたしかなさま。