Any life form of extraterrestrial or extradimensional origin.

A person, animal, plant, or other thing which is from outside the family, group, organization, or territory under consideration.

A foreigner residing in a country.

One excluded from certain privileges; one alienated or estranged.

To estrange; to alienate.

To transfer the ownership of something.

Not belonging to the same country, land, or government, or to the citizens or subjects thereof; foreign.

"alien subjects, enemies, property, or shores"

Very unfamiliar, strange, or removed.

"principles alien to our religion"

Pertaining to extraterrestrial life.