plop -- (the noise of a rounded object dropping into a liquid without a splash)
Overview of verb plop
The verb plop has 3 senses
plop -- (drop something with a plopping sound)
plop -- (drop with the sound of something falling into water)
plank, flump, plonk, plop, plunk, plump down, plunk down, plump -- (set (something or oneself) down with or as if with a noise; "He planked the money on the table"; "He planked himself into the sofa")
Overview of adv plop
The adv plop has 1 sense
plop, plunk -- (with a short hollow thud; "plop came the ball down to the corner of the green")