/ Dictionary / Index S side bet: Meaning and Definition of Find definitions for: side' bet" Pronunciation: [key] a bet made, as with another player, in addition to one's principal bet: a side bet as to which of us would draw the highest card. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. sidebar sideboard Related Content Daily Word Quiz: paradox Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language