stranger

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

• noun One who is neither a friend nor an acquaintance.
• noun A foreigner, newcomer, or outsider.
• noun One who is unaccustomed to or unacquainted with something specified; a novice.
• noun Law One that is neither privy nor party to a title, act, or contract.
• noun Archaic A visitor or guest.

from The Century Dictionary.

• To estrange; alienate.
• noun A name in Victoria and Tasmania for a labroid fish, Odax richardsoni. Also called rock-whiting.
• noun One who comes from another country or region; a foreigner.
• noun A person with whom one is not acquainted; one whose name and character are unknown.
• noun One who is ignorant (of) or unacquainted (with): with to.
• noun One not belonging to the house; a guest; a visitor.
• noun In law, one not privy or party to an act.
• noun Some thing popularly supposed or humorously said to betoken the approach of a stranger or guest, as guttering in a candle or a teastalk in a cup of tea.
• noun Specifically, in entomology, the noctuid moth Hadena peregrina: an English collectors' name.

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

• transitive verb obsolete To estrange; to alienate.
• noun One who is strange, foreign, or unknown.
• noun One who comes from a foreign land; a foreigner.
• noun One whose home is at a distance from the place where he is, but in the same country.
• noun One who is unknown or unacquainted; ; hence, one not admitted to communication, fellowship, or acquaintance.
• noun One not belonging to the family or household; a guest; a visitor.
• noun (Law) One not privy or party an act, contract, or title; a mere intruder or intermeddler; one who interferes without right.

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

• adjective comparative form of strange: more strange
• noun A person whom one does not know; a person who is neither a friend nor an acquaintance.
• noun An outsider or foreigner
• noun A newcomer.
• noun humorous One who has not been seen for a long time.
• verb obsolete, transitive To estrange; to alienate.

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

• noun an individual that one is not acquainted with
• noun anyone who does not belong in the environment in which they are found