Related Clues:

• Sit clumsily (with "down")
• Unceremonious fall
• Butt-hitting-beanbag chair sound
• The way to make an ape at Kew sit
• Penny-in-the-wishing-well sound
• Fall carelessly
• Sound associated with ripples
• Sound repeated before "fizz fizz," in ads
• How to win an election if you don't stand?
• Not a standing invit­ation
• Sound of a stone hitting water
• Rain sound
• Alka-Seltzer noise
• [frog lands in pond]
• Tiny splash