GNAW

(BITE) [verb] - to bite or chew (something) repeatedly, usually making a hole in it or gradually destroying itBabies like to gnaw hard objects when they're teething. [T]A dog lay under the table, gnawing (on) a bone. [T; I + preposition]How can I stop my son gnawing (at) his fingernails all day long? [T; I + preposition](figurative) Bad debts are continuing to gnaw (away) at (= make smaller) the bank's profits. [I]To gnaw something is to form it by biting repeatedly.A mouse had gnawed a hole in the rug.Rats had gnawed their way into a sack of corn.