/ Dictionary / Index O omission: Meaning and Definition of Find definitions for: o•mis•sion Pronunciation: (ō-mish'un), [key] — n. the act of omitting. the state of being omitted. something left out, not done, or neglected: an important omission in a report. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: omission (Thesaurus) omissible omissive Related Content Daily Word Quiz: spectral Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language