Definition:
* To bite or chew on something persistently and often with a scraping sound.
* To worry or distress someone.
* To wear away gradually by biting or chewing.
Examples:
* The dog gnawed on the bone.
* The thought of her failure gnawed at her conscience.
* The rats gnawed their way through the wall.
Synonyms:
* Bite
* Chew
* Nibble
* Worry
* Distress
* Consume
* Erode
* Wear away
Antonyms:
* Swallow
* Devour
* Soothe
* Comfort
* Repair
* Strengthen
Usage:
* Transitive verb: The rat gnawed the cheese.
* Intransitive verb: The dog gnawed at the bone for hours.
Etymology:
* From Old English *gnagan*, meaning "to bite, gnaw."