Verb (used with object) : to gnaw a hole through the wall.    From Dictionary.com. 

(A delightful true story of food, Paris, and the fulfillment of a lifelong dream) rongeur (ron-zhay) noun, masculine rodent, gnawer.    From Wordnik.com.  [rongeur - French Word-A-Day] Reference

Among them were the teeth of a gnawer, equalling in size and closely resembling those of the Capybara, whose habits have been described; and therefore, probably, an aquatic animal.    From Wordnik.com.  [Journal of researches into the geology and natural history of the various countries visited by H.M.S. Beagle] Reference

Before we had been long on the Barrier he developed mischievous habits and became a rope eater and gnawer of other ponies 'fringes, as we called the coloured tassels we hung over their eyes to ward off snow-blindness.    From Wordnik.com.  [The Worst Journey in the World Antarctic 1910-1913] Reference

I went back to the hitching post and gnawed at those knots, but got nowhere even though I’m a pretty good gnawer; the rope was thick and the knots were big and hard.    From Wordnik.com.  [To Fetch a Thief] Reference

He looks like a pillow gnawer to me.    From Wordnik.com.  [Latest Articles] Reference

Jealous of that gnawer of fish-bones?.    From Wordnik.com.  [The Lady Paramount] Reference

The beaver is the greatest gnawer of them all.    From Wordnik.com.  [Aboriginal America] Reference

Rongeur ron-zhay noun, masculine rodent, gnawer.    From Wordnik.com.  [rongeur - French Word-A-Day] Reference