musk deer vs deer

musk deer and deer both are nouns.

Word	Noun	Adjective	Verb	Adverb
musk deer	Yes	No	No	No
deer	Yes	No	No	No

As nouns, deer is a hypernym of musk deer; that is, deer is a word with a broader meaning than musk deer:

musk deer: small heavy-limbed upland deer of central Asia; male secretes valued musk
deer: distinguished from Bovidae by the male's having solid deciduous antlers

Other hypernyms of musk deer include cervid.

musk deer (noun)	deer (noun)
small heavy-limbed upland deer of central Asia; male secretes valued musk	distinguished from Bovidae by the male's having solid deciduous antlers