whitetail vs cervid

whitetail and cervid both are nouns.

Word	Noun	Adjective	Verb	Adverb
whitetail	Yes	No	No	No
cervid	Yes	No	No	No

As nouns, cervid is a hypernym of whitetail; that is, cervid is a word with a broader meaning than whitetail:

whitetail: common North American deer; tail has a white underside
cervid: distinguished from Bovidae by the male's having solid deciduous antlers

Other hypernyms of whitetail include deer.

whitetail (noun)	cervid (noun)
common North American deer; tail has a white underside	distinguished from Bovidae by the male's having solid deciduous antlers