alien

Concise Oxford English Dictionary © 2008 Oxford University Press:
alien/ˈeɪliən/

▶adjective

• 1 belonging to a foreign country.

  ■ (of a plant or animal species) introduced from another country and later naturalized.

• 2 unfamiliar and distasteful.

• 3 relating to or denoting beings from other worlds.

▶noun

• 1 a foreigner, especially one who is not a naturalized citizen of the country where they are living.

  ■ an alien plant or animal species.

• 2 a being from another world.

– derivatives
alienage noun,
alienness noun.

– origin ME: via OFr. from L. alienus ‘belonging to another’, from alius ‘other’.