Trefoil /(?)/

Tre·foil

Trefoil

n.
  1. Any plant of the genus Trifolium, which includes the white clover, red clover, etc.; -- less properly, applied also to the nonesuch, or black medic. See Clover, and Medic. (Bot.)
  2. An ornamental foliation consisting of three divisions, or foils. (Arch.)
  3. A charge representing the clover leaf. (Her.)