Yes, alien is a Scrabble word!

Verb

1. Transfer property or ownership

2. Arouse hostility or indifference in where there had formerly been love, affection, or friendliness

Adjective

1. Not contained in or deriving from the essential nature of something

2. Being or from or characteristic of another place or part of the world

Noun

1. A person who comes from a foreign country; someone who does not owe allegiance to your country

2. Anyone who does not belong in the environment in which they are found

3. A form of life assumed to exist outside the Earth or its atmosphere