Related Clues:

• It's a gas
• Fulton's power
• Sound of disapproval
• Ophidian sound
• Vent sound
• Kind of cleaning
• Greeting for the villain
• Snake's warning
• Kind of bath or boat
• Radiator sound
• Serpent's sound
• Bad reception?
• Catcall
• Fuse sound
• Letter opener, at times