noun
mistake; error; fault; oversight
Refers to a personal mistake, fault, or oversight, often implying some degree of responsibility or negligence. Commonly used in formal or serious contexts.
今回のミスは私の落ち度です。
This mistake is my fault.
彼に落ち度はなかったと判断された。
It was determined that he was not at fault.
Compound of 落ち (ochi, 'falling, omission', the continuative form of 落ちる) + 度 (do, 'degree, extent'). Literally 'degree of omission', it came to mean a mistake or fault attributable to someone.