An onomatopoeia for the sound or action of something heavy dropping or being placed heavily; a thudding, weighty impact.
彼は疲れてソファにどさりと横になった。
He flopped down on the sofa in exhaustion.
箱を床にどさりと置いた音が響いた。
The sound of the box being set down with a thud echoed.
荷物をどさりと降ろして、ため息をついた。
He dropped his luggage down with a thud and sighed.