Definitions for "Gnaw"
Keywords:  bite, chew, unwieldy, teeth, agony
To bite, as something hard or tough, which is not readily separated or crushed; to bite off little by little, with effort; to wear or eat away by scraping or continuous biting with the teeth; to nibble at.
To bite in agony or rage.
To use the teeth in biting; to bite with repeated effort, as in eating or removing with the teeth something hard, unwieldy, or unmanageable.
Keywords:  vex, plague, worry, trouble, constant
To trouble in a constant manner; to plague; to worry; to vex; -- usually used with at; as, his mounting debts gnawed at him.
Keywords:  fret, corrode, waste
To corrode; to fret away; to waste.
become ground down or deteriorate; "Her confidence eroded"