Related Clues:

• Speak harshly
• Boxer's "Back off!"
• [Return that bone at once, or I shall bare my teeth and yip!]
• Junkyard dog's warning
• [Mumble, mumble]
• Guard dog's warning
• "I'm mad!"
• Grade school basics, familiarly
• Dog's sound
• Growling sound
• Warning from a boxer
• Lock problem
• [This is frustrating!]
• Sound from a junkyard dog
• Angry dog's sound