trefoil vs medick

trefoil and medick both are nouns.

Word	Noun	Adjective	Verb	Adverb
trefoil	Yes	No	No	No
medick	Yes	No	No	No

As nouns, trefoil and medick are synonyms defined as:

trefoil and medick: any of several Old World herbs of the genus Medicago having small flowers and trifoliate compound leaves

Other synonyms of trefoil include medic.

trefoil (noun)	medick (noun)
an architectural ornament in the form of three arcs arranged in a circle	any of several Old World herbs of the genus Medicago having small flowers and trifoliate compound leaves
a plant of the genus Trifolium
any of several Old World herbs of the genus Medicago having small flowers and trifoliate compound leaves