Related Clues:

• Work on a bone, dog-style
• Enjoy a bone
• Agitate (with ''at'')
• Unyielding courage
• Act the rat
• Strength of character
• Nibble persistently
• Willingness to get dirty
• Chew (at)
• Work on a bone
• Work on ribs
• Nibble like a mouse
• Nibble away at
• Chew, like a dog on a bone
• Vex, with ''at''