Gnaw
Gnaw is a verb meaning to bite, chew, or nibble persistently on something with teeth, causing wear or damage. It can also imply a persistent sensation, such as hunger, pain, or worry, that consumes attention. The act can be performed by animals or humans, and the object is often wood, bone, or other hard substances.
In biology, gnawing is characteristic of rodents and some lagomorphs, which have specialized dental anatomy. They
In idiomatic use, phrases such as "gnaw at" describe something that troubles or preoccupies someone, as in
Etymology: The word is from Old English gnagan, related to Dutch knagen and German knagen; cognates appear