waif

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

• noun A homeless person, especially a forsaken or orphaned child.
• noun An abandoned young animal.
• noun A person, especially a young woman, who is thin or gaunt.
• noun Something found and unclaimed, as an object cast up by the sea.

from The Century Dictionary.

• noun Anything blown by the wind or drifted in by the ocean; a thing tossed abroad and abandoned; a stray or odd piece or article.
• noun In law: Goods found of which the owner is not known.
• noun Such goods as a thief, when pursued, throws away to prevent being apprehended.
• noun A wanderer; one who is lost; a neglected, homeless wretch: applied also to beasts.
• noun Same as weft or waft.
• Vagabond; worthless; ignoble; inferior. Also waff.

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

• noun (Eng. Law.) Goods found of which the owner is not known; originally, such goods as a pursued thief threw away to prevent being apprehended, which belonged to the king unless the owner made pursuit of the felon, took him, and brought him to justice.
• noun Hence, anything found, or without an owner; that which comes along, as it were, by chance.
• noun A wanderer; a castaway; a stray; a homeless child.

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

• noun obsolete Goods found of which the owner is not known; originally, such goods as a pursued thief threw away to prevent being apprehended, which belonged to the king unless the owner made pursuit of the felon, took him, and brought him to justice.
• noun obsolete Hence, anything found, or without an owner; that which comes along, as it were, by chance.
• noun A wanderer; a castaway; a stray; a homeless child.

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

• noun a homeless child especially one forsaken or orphaned