Other forms: aliens
Alien means belonging somewhere else, and strange because of it. An alien landscape, alien to me, alien species.
As a noun it means a foreign national in law and a creature from space in fiction, and the legal use is now often avoided as dehumanising. An alien species is one introduced from elsewhere, and an invasive one is an alien that spreads. Note that the Latin means belonging to another.
1adjectivealienBelonging somewhere else, and strange because of it.
“At first, the customs of her new country felt completely alien to her.”
2nounforeignA foreign national, or a creature from space.
“In the film, an alien lands in a small town and makes friends with a boy.”
Too few real examples of this word to estimate which sense is commonest.
alien is a quality of foreignness.
Latin alienus means belonging to another, from alius, other. Else, alias and alter come from the same otherness.
Proto-Indo-European
*h₂el- (other)
Latin
aliēnus — belonging to someone else”, later “exotic, foreign
Old French
alien
Middle English
alien
English, today
alien
From Middle English alien, a borrowing from Old French alien, aliene, from Latin aliēnus (“belonging to someone else”, later “exotic, foreign”), from Latin alius (“other”), from Proto-Indo-European h₂élyos. Related to English else.
Etymology from Wiktionary, CC BY-SA