any of numerous leguminous plants of the temperate genus Trifolium, having leaves divided into three leaflets and dense heads of small white, yellow, red, or purple flowers
2.
any of various related plants having leaves divided into three leaflets, such as bird's-foot trefoil
3.
a leaf having three leaflets
4. architecture
an ornament in the form of three arcs arranged in a circle
Derived forms
trefoiled (ˈtrefoiled)
adjective
Word origin
C14: from Anglo-French trifoil, from Latin trifolium three-leaved herb, from tri- + folium leaf
trefoil in American English
(ˈtriˌfɔɪl)
noun
1.
a.
any of a number of plants with leaves divided into three leaflets, as the clover, tick trefoil, and certain species of lotus
b.
a flower or leaf with three lobes
2.
any ornamental figure resembling a threefold leaf
Word origin
ME treyfoyle < Anglo-Fr trifoil < L trifolium, three-leaved plant < tri-, tri- + folium, a leaf: see foil2