A waif (from the Old French guaif, "stray beast") is a living creature removed, by hardship, loss or other helpless circumstance, from its original surroundings. The most common usage of the word is to designate a homeless, forsaken or orphaned child, or someone whose appearance is evocative of the same.
As such, the term is similar to a or street urchin, although the main distinction is volitional: a runaway youth might live on the streets, but would not properly be called a waif as the departure from one's home was an exercise of free will. Likewise, a person fleeing their home for purposes of safety (as in response to political oppression or natural disaster), is typically considered not a waif but a refugee.
Orphaned children, left to fend for themselves, are common as literary protagonists, especially in children's and fantasy literature. The characters Heathcliff in Emily Brontë's 1847 novel Wuthering Heights and Jo, the crossing sweeper in Charles Dickens' 1852 novel Bleak House are waifs. Dickens, it may be noted, has been called "the Master of Waif Literature."Bret Harte's 1890 novel A Waif of the Plains, set against the backdrop of the Oregon Trail in the 1850s, is another example. The children in A Series of Unfortunate Events are usually waifs, in between their unsuccessful stints in the care of various relatives. In modern adult fantasy writing, it could be argued that Kvothe of Patrick Rothfuss's The Kingkiller Chronicle (The Name of the Wind and The Wise Man's Fear) was a waif, and the stories include many flashback elements – as they are of Kvothe's life told by Kvothe – to the time when he indeed was a waif.