noun, noun or participle which takes 'suru', intransitive verb
sitting on the floor with legs tucked to one side
Colloquial term for a feminine floor-sitting posture where both legs are bent to one side, often associated with a demure or casual pose. Compare 横座り, which is a more formal term for the same posture.
See also: 横座り
彼女は床にお姉さん座りをしてテレビを見ていた。
She was sitting on the floor with her legs tucked to one side, watching TV.
お姉さん座りは、長時間だと足がしびれやすい。
When you sit with your legs tucked to one side for a long time, your legs tend to go numb.