/ Dictionary / Index G guard band: Meaning and Definition of Find definitions for: guard' band" Pronunciation: [key] — Radio. Radio. an unassigned range of radio frequencies either just above or just below the band of frequencies required for the signal transmitted by a broadcasting station. It helps to prevent interference in receivers between signals from different stations. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. guardant guard cell 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