D defs.my
Entry 1 sense Webster, 1913

Knapweed

· Knap·weed · IPA /ˈnæpwiːd/
01 n. The black centaury (Centaurea nigra); -- so called from the knoblike heads of flowers. Called also bullweed.
  1. 1.
    The black centaury (Centaurea nigra); -- so called from the knoblike heads of flowers. Called also bullweed.(Bot.) Also: bullweed