Noun: bull thistle
- European thistle with rather large heads and prickly leaves; extensively naturalized as a weed in the United States
"Bull thistle made the field difficult to traverse";
- boar thistle, spear thistle, Cirsium vulgare, Cirsium lanceolatum
Derived forms: bull thistles
Type of: plume thistle, plumed thistle
Encyclopedia: Bull thistle