yellow trefoil vs medic

yellow trefoil and medic both are nouns.

Word	Noun	Adjective	Verb	Adverb
yellow trefoil	Yes	No	No	No
medic	Yes	No	No	No

As nouns, medic is a hypernym of yellow trefoil; that is, medic is a word with a broader meaning than yellow trefoil:

yellow trefoil: prostrate European herb with small yellow flowers and curved black pods; naturalized in North America
medic: any of several Old World herbs of the genus Medicago having small flowers and trifoliate compound leaves

Other hypernyms of yellow trefoil include medick, trefoil.

yellow trefoil (noun)	medic (noun)
prostrate European herb with small yellow flowers and curved black pods; naturalized in North America	a medical practitioner in the armed forces
	any of several Old World herbs of the genus Medicago having small flowers and trifoliate compound leaves