1. Clover native to Ireland with yellowish flowers; often considered the true or original shamrock
   "hop trefoil is commonly worn on St. Patrick's Day";
   - hop clover, shamrock, lesser yellow trefoil, Trifolium dubium
    
2. Prostrate European herb with small yellow flowers and curved black pods; naturalized in North America
   "hop trefoil often grows in lawns and pastures";
   - black medick, hop clover, yellow trefoil, nonesuch clover, Medicago lupulina

Derived forms: hop trefoils

Type of: clover, medic, medick, trefoil

Encyclopedia: Hop trefoil