/ Dictionary / Index Q quack grass: Meaning and Definition of Find definitions for: quack' grass" Pronunciation: [key] — Inland North and North Midland U.S. a couch grass, Agropyron repens, a pernicious weed in cultivated fields. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. See also: quackgrass (Thesaurus) quackery quacksalver Related Content Daily Word Quiz: tactful Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language