omission, deletion -- (any process whereby sounds or words are left out of spoken words or phrases)
deletion -- ((genetics) the loss or absence of one or more nucleotides from a chromosome)
deletion, excision, cut -- (the omission that is made when an editorial change shortens a written passage; "an editor's deletions frequently upset young authors"; "both parties agreed on the excision of the proposed clause")
deletion -- (the act of deleting something written or printed)