emissary vs envoy

emissary and envoy both are nouns.

Word	Noun	Adjective	Verb	Adverb
emissary	Yes	No	No	No
envoy	Yes	No	No	No

As nouns, emissary and envoy are synonyms defined as:

emissary and envoy: someone sent on a mission to represent the interests of someone else

emissary (noun)	envoy (noun)
someone sent on a mission to represent the interests of someone else	a brief stanza concluding certain forms of poetry
	a diplomat having less authority than an ambassador
	someone sent on a mission to represent the interests of someone else