wapiti vs American elk

wapiti and American elk both are nouns.

Word	Noun	Adjective	Verb	Adverb
wapiti	Yes	No	No	No
American elk	Yes	No	No	No

As nouns, wapiti and American elk are synonyms defined as:

wapiti and American elk: large North American deer with large much-branched antlers in the male

Other synonyms of wapiti include Cervus elaphus canadensis, elk.

As nouns, wapiti and American elk are synonyms defined as:

Other synonyms of wapiti include Cervus elaphus, elk, red deer.

wapiti (noun)	American elk (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	common deer of temperate Europe and Asia