online medical dictionary | definition of trefoil

1. <botany> 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.

2. An ornamental foliation consisting of three divisions, or foils.

3. A charge representing the clover leaf.

Origin: L. Tres three + E. Foil leaf; cf. F. Frefle, It. Trifoglio, L. Trifolium. See Tri-, Foil leaf, and cf. Trifoly.

(01 Mar 1998)