Possible Clues:

• Not, by the sound of it, in size or in the mouth
• Broad-crowned tooth
• A built-in food-processor
• Containing a certain amount of substance used for grinding
• That's what you get for backbiting
• It may be filled before it bites
• It inflicts grinding damage - nothing left inside
• Canine's relative
• Canine companion
• Jaw protrusion