stag vs elk

stag and elk both are nouns.

Word	Noun	Adjective	Verb	Adverb
stag	Yes	No	Yes	No
elk	Yes	No	No	No

As nouns, elk is a hypernym of stag; that is, elk is a word with a broader meaning than stag:

Other hypernyms of stag include American elk, Cervus elaphus, red deer, wapiti.

stag (noun)	elk (noun)
adult male deer	large northern deer with enormous flattened antlers in the male; called `elk' in Europe and `moose' in North America
a male deer, especially an adult male red deer	common deer of temperate Europe and Asia
	large North American deer with large much-branched antlers in the male

stag (verb)	elk (verb)
watch, observe, or inquire secretly
give away information about somebody
attend a dance or a party without a female companion