alien

from The American Heritage® Dictionary of the English Language, 5th Edition.

• adjective Owing political allegiance to another country or government; foreign.
• adjective Belonging to, characteristic of, or constituting another and very different place, society, or person; strange. synonym: foreign.
• adjective Dissimilar, inconsistent, or opposed, as in nature.
• noun An unnaturalized foreign resident of a country.
• noun A person from another and very different family, people, or place.
• noun A person who is not included in a group; an outsider.
• noun A creature from outer space.
• noun Ecology An organism, especially a plant or animal, that occurs in or is naturalized in a region to which it is not native.
• transitive verb To transfer (property) to another; alienate.

from The Century Dictionary.

• To transfer or convey to another; make over the possession of: as, to alien a title or property. In this sense also written aliene.
• To make averse or indifferent; turn the affections or inclinations of; alienate; estrange.
• Residing under another government or in another country than that of one's birth, and not having rights of citizenship in such place of residence: as, the alien population; an alien condition.
• Foreign; not belonging to one's own nation.
• Wholly different in nature; estranged; adverse; hostile: used with to or from.
• noun A foreigner; one born in or belonging to another country who has not acquired citizenship by naturalization; one who is not a denizen, or entitled to the privileges of a citizen. In France a child born of residents who are not citizens is an alien.
• noun A stranger.
• noun An English statute of 1836 (6 and 7 Wm. IV. c. 11) providing for the registration of aliens; and one of 1844 (7 and 8 Vict. c. 66) allowing aliens from friendly nations to hold real and personal property for purposes of residence, and resident aliens to become naturalized.
• noun An English statute of 1847 (10 and 11 Vict. c. 83) concerning naturalization.

from the GNU version of the Collaborative International Dictionary of English.

• adjective Not belonging to the same country, land, or government, or to the citizens or subjects thereof; foreign.
• adjective Wholly different in nature; foreign; adverse; inconsistent (with); incongruous; -- followed by from or sometimes by to.
• adjective (Law) one who owes allegiance to a government at war with ours.
• noun A foreigner; one owing allegiance, or belonging, to another country; a foreign-born resident of a country in which he does not possess the privileges of a citizen. Hence, a stranger. See alienage.
• noun One excluded from certain privileges; one alienated or estranged.
• transitive verb rare To alienate; to estrange; to transfer, as property or ownership.

from Wiktionary, Creative Commons Attribution/Share-Alike License.

• noun A person, animal, plant, or other thing which is from outside the family, group, organization, or territory under consideration.
• noun A foreigner residing in a country.
• noun Any life form of extraterrestrial origin.
• adjective Pertaining to an alien.
• adjective Very unfamiliar, strange, or removed.
• verb transitive To estrange; to alienate.
• verb law To transfer the ownership of something.

from WordNet 3.0 Copyright 2006 by Princeton University. All rights reserved.

• noun a form of life assumed to exist outside the Earth or its atmosphere
• adjective being or from or characteristic of another place or part of the world
• adjective not contained in or deriving from the essential nature of something
• verb transfer property or ownership
• noun a person who comes from a foreign country; someone who does not owe allegiance to your country
• verb arouse hostility or indifference in where there had formerly been love, affection, or friendliness
• noun anyone who does not belong in the environment in which they are found