Definition from Wiktionary, the free dictionary
whittle (plural whittles)
- A knife; especially, a pocket knife, sheath knife, or clasp knife.
- A butcher's whittle.
- Rude whittles.
- He wore a Sheffield whittle in his hose.
- (transitive or intransitive) To cut or shape wood with a knife.
- (transitive) To reduce or gradually eliminate something (such as a debt).
Derived terms 
cut or shape wood with a knife
reduce or gradually eliminate something
- Webster's Seventh New Collegiate Dictionary, Springfield, Massachusetts, G.&C. Merriam Co., 1967