/ Dictionary / Index O omnibus clause: Meaning and Definition of Find definitions for: om'nibus clause" Pronunciation: [key] — Insurance. Insurance. a clause, esp. in an automobile liability policy, extending coverage to persons other than the insured named in the policy. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. omnibus omnidirectional 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