Trillium sessile tril·lium·ses·sile uncommon noun 1. trillium of northeastern United States with sessile leaves and red or purple flowers having a pungent odor Synonymsred trilliumtoadshadesessile trilliumTrillium sessile Related words Broader terms trillium WordNet 2.1 (Princeton University). WordNet 2.1 Copyright Princeton University. All rights reserved.
