na-adjective, noun
unclear; vague; imprecise; indistinct
Describes something that lacks clarity, precision, or definiteness. Can refer to statements, plans, memories, images, or criteria. Often used in formal or critical contexts.
彼の説明は不明確で、何を言いたいのかよくわからなかった。
His explanation was unclear, and I couldn't really understand what he wanted to say.
The plan was not approved because its objectives were vague.
この写真はピントが合っておらず、被写体が不明確だ。
This photo is out of focus, and the subject is indistinct.
不明瞭 is similar but often used for physical indistinctness (e.g., sound, vision) or unclear articulation, whereas 不明確 is broader and more abstract.
Compound of 不 (fu, 'not') + 明確 (meikaku, 'clear, precise'). The base 明確 is from 明 (mei, 'bright, clear') and 確 (kaku, 'certain, firm').