expatriation vs out-migration

expatriation and out-migration both are nouns.

Word	Noun	Adjective	Verb	Adverb
expatriation	Yes	No	No	No
out-migration	Yes	No	No	No

As nouns, expatriation and out-migration are synonyms defined as:

expatriation and out-migration: migration from a place (especially migration from your native country in order to settle in another)

Other synonyms of expatriation include emigration.

expatriation (noun)	out-migration (noun)
the act of expelling a person from their native land	migration from a place (especially migration from your native country in order to settle in another)
migration from a place (especially migration from your native country in order to settle in another)