Related Clues:

• Serpent's warning
• Indicator of indignation
• Jeer at
• (K) Scare word
• Scare word
• [Bad call!]
• Not a good reception
• Negative reaction
• Audible inhalation
• Scary shout
• Heckler's cry
• Poor reception?
• Fan's rebuke
• Cousin of a raspberry
• Starting-gate sound