Definitions of alien:

• 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
• noun:   a form of life assumed to exist outside the Earth or its atmosphere
• verb:   transfer property or ownership

  Example: "The will aliened the property to the heirs"

• verb:   arouse hostility or indifference in where there had formerly been love, affection, or friendliness
• adjective:   not contained in or deriving from the essential nature of something

  Example: "An economic theory alien to the spirit of capitalism"

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

  Example: "Alien customs"