expression, ichidan verb
sit with one knee raised; raise one knee while sitting on the floor
Describes a sitting posture on the floor where one knee is bent and raised, often with the foot flat on the floor, while the other leg remains folded or extended. Common in casual or informal settings.
彼は床に座って片膝を立てて話を聞いていた。
He sat on the floor with one knee raised, listening to the conversation.
片
If you sit with one knee up, it's easier to stand up.