trefoiled

adjective3

1. •
   Having the shape of a trefoil.

   • The knop is formed of three rams' heads, and the base, trefoiled-shaped, has three bosses […] — 1884
2. •
   Having a three-lobed extremity or extremities; of a cross: having ends which terminate in trefoils (similar or identical to bottony).
3. •
   Ornamented with trefoils projecting from the edges, as a bearing, partition, etc.