Rangifer tarandus vs deer

Rangifer tarandus and deer both are nouns.

Word	Noun	Adjective	Verb	Adverb
Rangifer tarandus	Yes	No	No	No
deer	Yes	No	No	No

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

Rangifer tarandus: Arctic deer with large antlers in both sexes; called `reindeer' in Eurasia and `caribou' in North America
deer: distinguished from Bovidae by the male's having solid deciduous antlers

Other hypernyms of Rangifer tarandus include cervid.

Rangifer tarandus (noun)	deer (noun)
Arctic deer with large antlers in both sexes; called `reindeer' in Eurasia and `caribou' in North America	distinguished from Bovidae by the male's having solid deciduous antlers