Noviro
咚
Simplified 咚
Traditional 咚
Pinyin dōng
Definition (onom.) boom (of a drum); knock (on the door)
门外又响了咚
Ménwài yòu xiǎng le dōng
There was another knock outside the door
You might also see
叮咚
dīng dōng
(onom.) ding dong; jingling of bells; clanking sound
咚咚
dōng dōng
(onom.) thud; thumping; thudding; pounding
咕咚
gū dōng
splash; (onom.) for heavy things falling down
壁咚
bì dōng
(slang) to kabedon; to corner (sb in whom one has a romantic interest) against a wall (loanword from Japanese 壁ドン "kabedon")
黑咕隆咚
hēi gu lōng dōng
pitch-black; pitch-dark