- Owing political allegiance to another country or government; foreign: alien residents. (adjective)
- Belonging to, characteristic of, or constituting another and very different place, society, or person; strange. See Synonyms at foreign. (adjective)
- Dissimilar, inconsistent, or opposed, as in nature: emotions alien to her temperament. (adjective)
- An unnaturalized foreign resident of a country. Also called noncitizen. (noun)
- A person from another and very different family, people, or place. (noun)
American Heritage(R) Dictionary of the English Language, Fifth Edition. Copyright (c) 2011 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.