Gnaw dream meaning is explained below using 2 different sources. Each interpretation is shown with its source.

Interpretation 1 — Betty Bethards

Something eating away at you, bothering you, taking energy. Examine level of stress, anxieties, fears; rid self of extra burdens and negative thinking.
Source: The Dream Books Symbols Author: Betty Bethards

Interpretation 2 — Versatile - Anonymous

See bite / bitten
Source: Dream Meanings of Versatile Author: Versatile - Anonymous