Answer: plop

AnswerCrossword Clue
PLOPSit without ceremony
PLOP[frog lands in pond]
PLOPAlka Seltzer sound
PLOPKer finisher
PLOPAlka-Seltzer-landing-in-water sound
PLOPDropping-into-water sound
PLOPSit down heavily
PLOPAlka-Seltzer jingle starter
PLOPFall into a chair
PLOPSink heavily
PLOPLeaky faucet sound
PLOPSound repeated before "fizz fizz," in ads
PLOPAlka-Seltzer sound?
PLOPMake a splash
PLOPSound of a drop
PLOPDrip's sound
PLOPDripping sound
PLOPDrop like drops
PLOPDrop heavily
PLOPRain sound
plopplopping sound or fall
PLOPSplashing sound
PLOPAlka-Seltzer-in-water sound
PLOPRaindrop sound
PLOPKerplunk
PLOPSplash
PLOPFizz preceder
PLOPCoin-in-a-fountain sound
PLOPFizz lead-in
PLOPRainspout sound
PLOPSoft landing
PLOPPenny-in-the-wishing-well sound
PLOPWet sound
PLOPAlka-Seltzer sound
PLOPFall heavily
PLOPFall sound
PLOPSit heavily
PLOPPlunk down
PLOPFall with force
PLOPOnomatopoetic water sound