PERPENT, or PARPENT STONES  , in architecture, bond or " through stones," the &a-rovot of the Greeks and Romans, long stones going right through walls, and tying them together from face to face . The O . Fr. par pain, modern parpaing, from which this word is derived, is obscure in origin . It may be from a supposed Lat. perpago, perpaginis, formed like compago, a joint, from the root of pangere, to fasten, and meaning " some-thing fastened together," or from some popular corruption of Lat. perpendiculum, plummet or plumb-line (pir or pendere, to hang), referring to the smooth perpendicular faces of the stone .