crested wheatgrass cres·tedw·heatg·rass uncommon noun 1. Eurasian grass grown in United States great plains area for forage and erosion control Synonymscrested wheatgrasscrested wheat grassfairway crested wheat grassAgropyron cristatum Related words Broader terms wheatgrass WordNet 2.1 (Princeton University). WordNet 2.1 Copyright Princeton University. All rights reserved.