Setaria se·ta·ria uncommon noun 1. annual or perennial grasses of warm regions: bristlegrasses Synonymsgenus Setaria Related words Word family Setaria glaucaSetaria italicaSetaria italica rubrofructaSetaria italica stramineofructaSetaria viridis Broader terms monocot genus Parts Gramineae Part of bristlegrassfoxtail millet WordNet 2.1 (Princeton University). WordNet 2.1 Copyright Princeton University. All rights reserved.