1. bite or chew on with the teeth

- gnaw an old cracker

Definition categories: contact, chew, jaw, manducate, masticate, bite

2. become ground down or deteriorate

Similar word(s): erode

Definition categories: change, crumble, decay, dilapidate

Sentences with gnaw as a verb:

- The dog gnawed the bone until it broke in two.

- Her comment gnawed at me all day and I couldn't think about anything else.