/ Dictionary / Index O on-air: Meaning and Definition of Find definitions for: on-air Pronunciation: (on'âr', ôn'-), [key] — adj. broadcasting: an announcer with five years of on-air experience. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: on-air (Thesaurus) onagraceous onanism Related Content Daily Word Quiz: rustic Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language