to cut, bite, and wear away bit by bit with the teeth
to make by gnawing: to gnaw a hole
to consume; wear away; corrode
to torment, as by constant pain, fear, etc.; harass
intransitive verb
to bite repeatedly: with on, away, at, etc.
to produce a biting, consuming, corroding, eroding, tormenting, etc. effect: with on, at, etc.: waves gnawed away at the shore; fear gnawed on his consciousness