/ Dictionary / Index G guard cell: Meaning and Definition of Find definitions for: guard' cell" Pronunciation: [key] — Bot. Bot. either of two specialized epidermal cells that flank the pore of a stoma and usually cause it to open and close. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. guard band guard dog 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