Meaning of alien
Definition of alien
(adj)
not contained in or deriving from the essential nature of something; "an economic theory alien to the spirit of capitalism"; "the mysticism so foreign to the French mind and temper"; "jealousy is foreign to her nature"
being or from or characteristic of another place or part of the world; "alien customs"; "exotic plants in a greenhouse"; "exotic cuisine"
(noun)
a person who comes from a foreign country; someone who does not owe allegiance to your country