/ Dictionary / Index B bird grass: Meaning and Definition of Find definitions for: bird' grass" Pronunciation: [key] a grass, Poa trivialis, grown in temperate regions of North America largely for lawns and turf. the knotgrass, Polygonum aviculare. Random House Unabridged Dictionary, Copyright © 1997, by Random House, Inc., on Infoplease. bird-footed dinosaur birdhouse Related Content Daily Word Quiz: secular Analogy of the Day: Today’s Analogy Spelling Bee: Today’s Spelling Bee Frequently Misspelled Words Frequently Mispronounced Words Easily Confused Words Writing & Language