不確か|ふたしかfutashika[2]nakadaka (mid-high)

1. na-adjective, noununreliable; uncertain; indefinite; unclear
   結果けっかはまだ不確ふたしかである。↗

   The result is still in doubt.

• Synonym不確定ふかくていWrittenWritten/formal prose. Means not yet settled or decided, as in 「日程は不確定」; leans toward the undecided and is not used for hazy memories.
• Synonym不確実ふかくじつWrittenWritten/formal prose. Something not certain or dependable, as in 「不確実な情報」 and 「不確実性」; also common in economic forecasting.
• SynonymあやふやNeutralColloquial. Vague and undependable, as in 「あやふやな記憶」; the closest synonym to 「不確か」.
• Synonym曖昧あいまいNeutralVague or ambiguous, as in 「曖昧な返事」; leans toward evasive attitudes and noncommittal wording.
• Related不正確ふせいかくWrittenWritten/formal prose. Points to errors and inaccuracy in data or statements, as in 「不正確な情報」; 「不確か」 stresses unreliability and lack of confidence.
• Related不明ふめいNeutralMeans unknown or unidentified, as in 「原因不明」; centers on missing information rather than unreliability.
• Related不鮮明ふせんめいWrittenWritten/formal prose. For blurry images or colors, as in 「画像が不鮮明」; a visual lack of sharpness.
• Related頼りないたよりないNeutralColloquial. Unreliable and not to be counted on; mostly said of people, as in 「頼りない上司」.
• RelatedうやむやNeutralLeaving things vague or letting them trail off unresolved, as in 「うやむやにする」; concerns how a matter is handled.
• Related不定ふていWrittenWritten/formal prose. Not fixed or settled, as in 「住所不定」; stresses constant change.
• RelatedおぼつかないNeutralColloquial. Suggests an uncertain outlook or unsteady footing, as in 「足元が覚束ない」; carries a note of worry.
• RelatedおぼろげWrittenWritten/formal prose. Describes hazy memories or outlines, as in 「おぼろげな記憶」; leans on the visual impression of dimness.
• Related不明瞭ふめいりょうWrittenWritten/formal prose. For unclear explanations or pronunciation, as in 「不明瞭な説明」; focuses on unclear expression.
• Related宙ぶらりんちゅうぶらりんNeutralColloquial. Left hanging or undecided, as in 「宙ぶらりんの状態」; focuses on the situation one is left in.
• Related心もとないこころもとないNeutralColloquial. Leaves you uneasy or feeling short of support, as in 「一人では心もとない」; centers on the anxious feeling.
• Related曖昧模糊あいまいもこWrittenA four-character idiom for vagueness, with an emphatic written/formal flavor; rarely used.
• Antonym確かたしかNeutralAntonym. Sure and dependable, the direct opposite of the unreliability of 「不確か」.
• Antonym明確めいかくWrittenAntonym. Written/formal prose for clear and definite, opposing the unclearness of 「不確か」.
• Antonym確実かくじつNeutralAntonym. Certain and free of error, as in 「確実な方法」; the opposite of 「不確か」.

Use 「不確か」 for memories or information you cannot rely on or feel unsure about, as in 「不確かな情報」 and 「記憶が不確か」. In speech, 「あやふや」 is the closest match. Pick 「不正確」 for inaccurate data or statements, 「不確定」 for things not yet decided, 「朧気」 or 「不鮮明」 for hazy sights and memories, 「不明瞭」 for unclear explanations, and 「頼りない」 for unreliable people. The antonyms are 「確か」, 「明確」 and 「確実」.

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

1. 確たしかでないこと。あやふや。不ふ確実かくじつ。