PILLION  , a

light saddle without pommel or bow, especially a pad fastened to the back of an ordinary saddle, as a seat for another person, generally a woman . Pillions were also used to support baggage . They were in common use from the 16th to the 18th centuries . The word appears to have been adapted into English from the Irish pillin, cushion, formed from Lat. pellis, skin . In the sense of a hat worn by a priest or doctor of divinity, " pillon " or " pylion " occurs in the 15th and 16th centuries . This is probably from Lat. pileus, a conical felt hat or cap, Gr. wcaor .