Noah Webster's New International Dictionary of the English Language

1. (v. t.) 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.

2. (v. t.) To bite in agony or rage.

3. (v. t.) To corrode; to fret away; to waste.

4. (v. i.) To use the teeth in biting; to bite with repeated effort, as in eating or removing with the teeth something hard, unwieldy, or unmanageable.