c. 1300, "strange, foreign," from Old French alien "strange, foreign;" as a noun, "an alien, stranger, foreigner," from Latin alienus "of or belonging to another, not one's own, foreign, strange," also, as a noun, "a stranger, foreigner," adjective from alius (adv.) "another, other, different" (from PIE root *al- (1) "beyond").
The meaning "residing in a country not of one's birth" is from mid-15c. The sense of "wholly different in nature" is from 1670s. The meaning "not of this Earth" is recorded by 1920. An alien priory (mid 15c.) is one owing obedience to a religious jurisdiction in a foreign country.
"foreigner, citizen of a foreign land," early 14c., from alien (adj.) or from noun use of the adjective in French and Latin. In the science fiction sense "being from another planet," from 1953.
updated on September 16, 2022