1. (plural) Stolen goods thrown away by a thief in flight.
2. Property found but unclaimed.
3. A stray person or animal; a homeless or neglected child.
4. (botany) A "stray" plant, introduced out of its normal range but unable to establish itself and soon disappearing.
Or, roughly, any thing removed from its original surroundings by circumstances beyond its control.
The "waif look" in fashion refers to someone who is unusually thin, alluding to the appearance of neglected children.
Etymology: Old French guaif, "ownerless property, something lost".