Correct

咕咚

/ gūdōng /
Strokes

Definition

splash/(onom.) for heavy things falling down

Example

As an Onomatope

thud; splash; plump; plop

1
kuàngquánshuǐ
矿泉水
  
,
dōngdōng
咕咚咕咚
le
kǒu
  

He took a bottle of mineral water and drank with some gulps.

2
diǎn
词典
dōng
咕咚
shēng
diào
zài
shang
地上
  

The dictionary fell to the ground with a thud/thump.

3
dōng
咕咚
shēng
tiàojìn
跳进
河里

splash/plop into the river; dive into the river with a splash/plop