(topology) A knot formed by joining the two loose ends of a overhand knot to form a knotted loop; the simplest non-trivial knot.

(heraldry) tréflé

plural of bean trefoil

Anagyris foetida, a leguminous shrub of southern Europe with trifoliate leaves.

(religious) Not kosher.

The genus Lotus and various species in it, especially common birdsfoot trefoil (Lotus corniculatus), a flowering plant native to grassland in Eurasia and North Africa.

Medicago arborea, a plant with yellow flowers.

One of several species in the genus Desmodium in the legume family

Synonym of trifluralin

(historical) A communal settlement in mediaeval Wales including a communal cattle pasture and smithy.