gnawn

transitive verb gnawed, gnawed or Raregnawn, gnawing

1. to cut, bite, and wear away bit by bit with the teeth
2. to make by gnawing: to gnaw a hole
3. to consume; wear away; corrode
4. to torment, as by constant pain, fear, etc.; harass

intransitive verb

1. to bite repeatedly: with on, away, at, etc.
2. 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