kowtow, pause, stop

頓 is composed of 屯 (store up) and 頁 (page). 屯 is a pictograph of a plant as it sprouts, while 頁 represents the head. When a plant sprouts, its top breaks through the ground. Therefore, the original meaning of 頓 is to knock the head against the ground, and it extends to the meaning of pausing or stopping temporarily.