Quote (kfmonster @ Mar 10 2012 01:49pm)

al·ien
   [eyl-yuhn, ey-lee-uhn]
noun
1. a resident born in or belonging to another country who has not acquired citizenship by naturalization ( distinguished from citizen).
2. a foreigner.
3. a person who has been estranged or excluded.
4. a creature from outer space; extraterrestrial.

I believe that #4 technically is an example of the other 3 definitions, making it unnecessarily a definition.
Stupid dictionary!