omis·sion /oˈmɪʃən, ə-/
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.
n 1: a mistake resulting from neglect [syn: skip]
2: something that has been omitted; "she searched the table for
3: any process whereby sounds are left out of spoken words or
phrases [syn: deletion]
4: neglecting to do something; leaving out or passing over