expatriate vs emigrate

expatriate is a noun but emigrate is not a noun.

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

As verbs, emigrate is a hypernym of expatriate; that is, emigrate is a word with a broader meaning than expatriate:

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

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

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