Refers to something that was accidentally left out or overlooked, often in documents, procedures, or considerations.
There was an omission in the report.
Please check so that there are no oversights.
Standard kanji spelling.
Variant with simplified okurigana.
Compound of 為 (し, 'doing') + 落とし (おとし, 'dropping'), literally 'dropping what should be done', leading to the meaning of omission or oversight.