Refers to an avoidable mistake, oversight, or lapse in judgment, often with a sense of regret. Common in the phrase 不覚を取る (to suffer a defeat or make a blunder).
あんなミスをするとは不覚だった。
It was a blunder to make that kind of mistake.
Rare, literary use for loss of consciousness or being unaware. More commonly expressed as 意識不明 or 気絶 in modern Japanese.
その一撃で彼は不覚に陥った。
He fell unconscious from that single blow.
Letting my guard down during the match was a blunder.
shallow thinker; indecisive person
tears shed in spite of oneself; involuntary tears
unconscious; blacked out; having no memory of one's actions
pitcher's misjudgment; mistake pitch
Standard kanji spelling.
From Middle Chinese 不覚 (bjuw kæwk, literally 'not awake/aware'). The kanji 不 (not) and 覚 (awake, perceive) combine to mean 'unawareness' or 'failure to realize', which extended to 'blunder' in Japanese.