adverb taking the 'to' particle, adverb
Mimetic word for a heavy thudding sound, such as a large object falling or a heavy body hitting the floor.
大きな荷物がドタンと落ちた。
A large package fell with a thud.
彼は疲れてベッドにドタンと倒れ込んだ。
Exhausted, he collapsed onto the bed with a thud.