noun
klop; klunk; whonk; crash; thump
Onomatopoeic noun for a heavy, dull impact sound, like a thud or crash.
ガツンという音がして、車が壁にぶつかった。
There was a thump, and the car hit the wall.
adverb taking the 'to' particle
with a heavy impact; forcibly
Adverbial use with と, describing an action done forcefully or with a heavy impact.
See also: がつんと言う
彼は机をガツンと叩いた。
He banged the desk forcefully.