omission,n.1. A failure to do something; esp., a neglect of duty <the complaint alleged that the driver had committed various negligent acts and omissions>.2. The act of leaving something out <the contractor’s omission of the sales price rendered the contract void>.3. The state of having been left out or of not having been done <his omission from the roster caused no harm>.4. Something that is left out, left undone, or otherwise neglected <the many omissions from the list were unintentional>. — Formerly also termed omittance. — omit,vb. — omissive, omissible,adj.

[Blacks Law 8th]