The term 'thrash or thresh' can refer to the act of flailing, which is a vigorous movement of the arms and legs. Flailing is often used to describe the motion of beating something with a stick or other object. It is also used to describe the motion of stirring something vigorously. In farming, threshing is the process of separating the grain from the chaff, which is done by flailing the stalks of grain against a hard surface.