Cenchrus cench·rus uncommon noun 1. a genus of grasses of the family Gramineae that have burs Synonymsgenus Cenchrus Related words Word family Cenchrus ciliarisCenchrus tribuloides Broader terms monocot genus Parts Gramineae Part of burgrasssandbur WordNet 2.1 (Princeton University). WordNet 2.1 Copyright Princeton University. All rights reserved.