E. Cobham Brewer 18101897. Dictionary of Phrase and Fable. 1898.
To cut away with a knife or whittle; to reduce; to encroach. In Cumberland, underpaid schoolmasters used to be allowed Whittle-gaiti.e. the privilege of knife and fork at the table of those who employ them.
The Americans whittled down the royal throne; whittled out a commonwealth; whittle down the forest trees; whittle out a railroad; whittle down to the thin end of nothing. (Saxon, hwytel, a large knife.)
We have whittled down our loss extremely, and will not allow a man more than 350 English slain out of 4,000.Walpole.