expression, godan verb (-ru)
throw oneself down; lie down (heavily)
Describes lying down in a relaxed, heavy, or careless manner, often with a sense of flopping or sprawling. The adverb ごろりと adds an onomatopoeic nuance of rolling or thudding down.
See also: 横になる
疲れたので、畳の上にごろりと横になった。
I was tired, so I flopped down on the tatami.
彼はソファにごろりと横になってテレビを見ている。
He's sprawled on the sofa watching TV.