The noise of a rounded object dropping into a liquid without a splash.
Drop something with a plopping sound.
Drop with the sound of something falling into water.
Set (something or oneself) down with or as if with a noise.
Dutch: neerploffen, neervallen, neerzakken, neerzinken
With a short hollow thud:
— Plop came the ball down to the corner of the green.
debug info: 0.1098