Cervus elaphus vs red deer

Cervus elaphus and red deer both are nouns.

Word	Noun	Adjective	Verb	Adverb
Cervus elaphus	Yes	No	No	No
red deer	Yes	No	No	No

As nouns, Cervus elaphus and red deer are synonyms defined as:

Other synonyms of Cervus elaphus include American elk, elk, wapiti.

Cervus elaphus (noun)	red deer (noun)
common deer of temperate Europe and Asia	common deer of temperate Europe and Asia