thrash [OE] Thrash and thresh are variant forms of the same Old English word. The Germanic root sense was probably ‘to tramp with the feet’. Thrash was used for treading out corn by men or oxen; when beating with a flail replaced treading, thresh was restricted to producing grain, and thrash extended to more generalized notions of knocking, beating, and striking. In threshold [OE] the first element is related to thresh in the Germanic sense ‘tread’, but the origin of the second element remains unknown.