American elk vs Cervus elaphus canadensis

American elk and Cervus elaphus canadensis both are nouns.

Word	Noun	Adjective	Verb	Adverb
American elk	Yes	No	No	No
Cervus elaphus canadensis	Yes	No	No	No

As nouns, American elk and Cervus elaphus canadensis are synonyms defined as:

American elk and Cervus elaphus canadensis: large North American deer with large much-branched antlers in the male

Other synonyms of American elk include elk, wapiti.

American elk (noun)	Cervus elaphus canadensis (noun)
large North American deer with large much-branched antlers in the male	large North American deer with large much-branched antlers in the male
common deer of temperate Europe and Asia