/ Dictionary / Index O on-season: Meaning and Definition of Find definitions for: on-sea•son Pronunciation: (on'sē'zun, ôn'-), [key] — adj. being a time of year that is the busiest or most popular for a specific activity; in season: on-season airfares. —adv. in or during the busiest season: to travel on-season. —n. a time of year that is the busiest or most popular for a specific activity: We stayed at the resort in the on-season. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. on-seam onset Related Content Daily Word Quiz: impetuous Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language