alien
al-ien
noun
A person residing in a country but not a citizen.
"He was registered as an alien."
adjective
Unfamiliar, strange, or from a different place or culture.
"The customs felt alien to her."
noun
A hypothetical being from another planet or world.
"The film featured a friendly alien."
Thesaurus
Synonyms: foreigner, noncitizen, outlander, extrinsic, foreign, extraterrestrial being, extraterrestrial, alienate, exotic, strange, unknown, stranger
Antonyms: acquaintance, citizen, friend