The act of farting in the shower as water muffles the noise causing it to sound somewhat like Donald Duck laughing.
by StolenDignity March 22, 2012

When a fart is conducted in the shower and the water running over the anus makes it sound like a duck quacking.
Friend 1: "I farted in the shower earlier and it sounded like Donald Duck laughing."
Friend 2: "SHOWER QUACK!"
Friend 2: "SHOWER QUACK!"
by Unwept, the Lone Magpie March 23, 2012
