Plewink
n. The sound made by a turd when it plops into the toilet.
After a long, burning struggle that tested the elastic limits of Barry's anus, the fetid mass finally gave way to gravity and, like an 8-ball lobbed into a pond, splashed into the toilet with a resolute plewink. Barry wiped his tears and, through his legs looked down upon his clumpy marble-brown creation with swelling pride: it was Barry's greatest accomplishment of the day.