What does "gnaw" mean?

Gnaw: To bite in agony or rage. They gnawed their tongues for pain. Rev. xvi.

Additional senses

  1. 2.3. To corrode; to fret away; to waste.
  2. 3.To use the teeth in biting; to bite with repeated effort, as in eating or removing with the teethsomething hard, unwiedly, or unmanageable. I might well, like the spaniel, gnaw upon the chain that ties me. Sir P. Sidney.

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