躺着用英语可以说是 "lying down"。这个短语来自英语中的动词 "lie"，表示 "躺下" 的意思。它的名词形式是 "position"，表示 "躺着的姿势"。

例句：

I like to lie down and relax after a long day at work. (我喜欢工作一天后躺下来放松。)

He was lying down on the couch, watching TV. (他躺在沙发上看电视。)

She assumed a lying down position on the floor. (她在地板上躺下来。)