From the Godfather movie:
Barzini's people chisel my territory and we do nothing about it. Soon I'll have no place in Brooklyn to hang my hat.
The only meaning I've found for the word chisel is
a tool with a flat metal blade used for cutting wood or stone
It also means doing some work with that tool. In the context it seems nonsensical to say the least, so I guess it's an idiomatic expression. I'd also guess that Barzini's people getting control in his ground, gradually pushing him out of his affairs there.