- alien (adj.)
- mid-14c., "strange, foreign," from O.Fr. alien, from L. alienus "of or belonging to another," adj. form of alius "(an)other" (see alias). Meaning "of another planet" first recorded 1944 in science fiction writing; the noun in this sense is from 1953. The noun sense of "foreigner" is first attested early 14c. An alien priory (c.1500) is one owing obedience to a mother abbey in a foreign country.