Definition of "Alien" :

noun: a form of life assumed to exist outside the Earth or its atmosphere

noun: a person who comes from a foreign country; someone who does not owe allegiance to your country

noun: anyone who does not belong in the environment in which they are found

verb: transfer property or ownership

"The will aliened the property to the heirs."

adjective: being or from or characteristic of another place or part of the world

"Alien customs."

adjective: not contained in or deriving from the essential nature of something

"An economic theory alien to the spirit of capitalism."