1. Being or from or characteristic of another place or part of the world
   "alien customs";
   - exotic
    
2. Not contained in or deriving from the essential nature of something
   "an economic theory alien to the spirit of capitalism";
   - foreign
    
3. Strange or disturbing
   "His behaviour seemed alien to his usual self"

1. A person who comes from a foreign country; someone who does not owe allegiance to your country
   "As an alien, he was not eligible to vote in the national election";
   - foreigner, noncitizen, outlander
    
2. Anyone who does not belong in the environment in which they are found
   "The alien felt out of place in the unfamiliar culture";
   - stranger, unknown
    
3. A form of life assumed to exist outside the Earth or its atmosphere
   "The search for alien beings is a major focus of the SETI project";
   - extraterrestrial being, extraterrestrial, ET

1. Transfer property or ownership
   "The will aliened the property to the heirs";
   - alienate

Derived forms: aliened, aliening, aliens

See also: extrinsic, foreign, strange

Type of: hypothetical creature, interloper, intruder, transfer, traveler [US], traveller [Brit, Cdn], trespasser

Antonym: acquaintance

Encyclopedia: Alien