emigrate vs expatriate

emigrate is not a noun while expatriate is a noun.

Word	Noun	Adjective	Verb	Adverb
emigrate	No	No	Yes	No
expatriate	Yes	No	Yes	No

As verbs, expatriate is a hyponym of emigrate; that is, expatriate is a word with a more specific, narrower meaning than emigrate:

emigrate: leave one's country of residence for a new one
expatriate: move away from one's native country and adopt a new residence abroad

emigrate (noun)	expatriate (noun)
	a person who is voluntarily absent from home or country

emigrate (verb)	expatriate (verb)
leave one's country of residence for a new one	move away from one's native country and adopt a new residence abroad
	expel from a country