gnaw

To bite something persistently, especially something tough.ambitransitive

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

To produce excessive anxiety or worry.intransitive

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

To corrode; to fret away; to waste.

• VVots thou vvho's returnd, / The unthrift Bonvile, ragged as a ſcarre-crovv / The VVarres have gnavv'd his garments to the skinne: […]

The act of gnawing.

• give something a gnaw
• have a gnaw of a bone