Answer: gnawon

AnswerCrossword Clue
GNAWONEat at
GNAWONEat at, as one's conscience
GNAWONEat, like a rat
GNAWONEat away at, like a rat
GNAWONChomp at
GNAWONBite with repeated effect.
GNAWONChew, as a steak bone