trefoil

noun

• a small European plant of the pea family with yellow flowers and three-lobed cloverlike leaves.

  • Genera Trifolium and Lotus, family Leguminosae: several species, in particular the bird’s-foot trefoil
• a plant with three-lobed leaves similar to trefoil.
• an ornamental design of three rounded lobes like a clover leaf, used typically in architectural tracery.
• a thing having three parts; a set of three:a trefoil of parachutes lowers the shuttle’s used rockets to Earth
• [as modifier] denoting something shaped in the form of a trefoil leaf:trefoil windows