/ Dictionary / Index S side band: Meaning and Definition of Find definitions for: side' band" Pronunciation: [key] — Radio. Radio. the band of frequencies at the sides of the carrier frequency of a modulated signal. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. side arm sidebar Related Content Daily Word Quiz: endear Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language