|  | 
Definition of Spear thistle
1. Noun. European thistle with rather large heads and prickly leaves; extensively naturalized as a weed in the United States. 
Exact synonyms: Boar Thistle, Bull Thistle, Cirsium Lanceolatum, Cirsium Vulgare
Generic synonyms: Plume Thistle, Plumed Thistle
Generic synonyms: Plume Thistle, Plumed Thistle



