To bite at or chew on something persistently.

To cause persistent discomfort or anxiety.

सताना

English Usage: The thought of failing the exam began to gnaw at her.

Hindi Usage: परीक्षा में असफल होने का खयाल उसे सताने लगा।

A persistent biting or chewing.

चबाना

English Usage: His constant gnaw during the meeting was very distracting.

Hindi Usage: मीटिंग के दौरान उसका लगातार चबाना बहुत परेशान करने वाला था।