Related Clues:

• Growl viciously
• 'Grrr!' is one
• Surly growl
• Junkyard warning, maybe
• Tie-up, real or figurative
• Sound from a cornered cur
• Knitting annoyance
• Warning from a canine
• Confused situation — speak harshly
• Growl angrily
• Sound from an active guard dog
• Warning from a Weimaraner