Hop clover Meaning, Definition & Usage

  1. noun prostrate European herb with small yellow flowers and curved black pods; naturalized in North America
    black medick; yellow trefoil; nonesuch clover; Medicago lupulina.
  2. noun clover native to Ireland with yellowish flowers; often considered the true or original shamrock
    shamrock; Trifolium dubium; lesser yellow trefoil.

WordNet

Definitions
  1. (Bot.), a species of yellow clover having heads like hops in miniature (Trifolium agrarium, and T. procumbens).

Webster 1913