Definify.com
Webster 1913 Edition
Omission
1.
The act of omitting; neglect or failure to do something required by propriety or duty.
The most natural division of all offenses is into those of
omission
and those of commission. Addison.
2.
That which is omitted or is left undone.
Webster 1828 Edition
Omission
OMIS'SION
,Noun.
1.
Neglect or failure to do something which a person had power to do, or which duty required to be done. Omission may be innocent or criminal; innocent, when no duty demands performance, but criminal when duty is neglected.The most natural division of all offenses, is into those of omission and those of commission.
2.
A leaving out; neglect or failure; to insert or mention; as the omission of a word or clause.