A mammal of the order Rodentia, characterized by long incisors that grow continuously and are worn down by gnawing.
"The squirrel's sharp teeth kept growing all year because it spent its days tirelessly gnawing on acorns to wear them down."
Gnawing; biting; corroding; applied to a destructive variety of cancer or ulcer.
"The doctor warned that if the tumor continued its relentless gnawing on his spine, he might lose mobility within weeks."
The word rodent comes from the Latin rōdēns, which means "gnawer." It is derived from the verb rōdō, meaning "to gnaw."