rifle [ME] The Old French rifler meant both ‘to plunder’ and to ‘to scratch’. The plunder sense developed via ‘search for valuables’ into ‘to search thoroughly’ [LME]. The word was then re-borrowed from French in the ‘scratch’ sense for the making of grooves in the barrel of a gun [E17th]. These rifled guns then became known as rifles [M18th]. Riff-raff [ME], formerly written as riff and raff, is probably also from rifler combined with raffler ‘to carry off’. The sense ‘disreputable person’ would have developed in much the same way as *vulgar and *hoi polloi.