Related Clues:
- Reptilian warning found in 17-, 24-, 50- and 61-Across
- Feline's warning
- Show disapproval? It's conveyed by this sound
- Express disapproval at some of this song
- Cottonmouth's warning
- Sound of a ball losing air
- Sound of a ball going flat
- Sound of a tire going flat?
- Flat-tire sound
- Sound of a flat tire
- Angry snake's sound
- Snake "talk"
- Kettle or snake sound
- Noise at a bad stand-up performance
- Sound of 7-Down