interj. (context onomatopoeia English) The sound of a small object falling in liquid. n. An instance of this sound.
Usage examples of "ploop".
There was a ploop, and a voice from the lift wall said, "Lifts may be held stopped for no more than one hundred seconds, to avoid congestion of the system.
I'm wondering if I used to be a Ploop, but I'm too tired to think about it or even care right now.