pillion

A pillion is a mostly British English term for a secondary pad, cushion, or seat behind the main seat or saddle on a horse, motorcycle, bicycle or moped. A passenger in this seat is said to "ride pillion" or may be referred to as a "pillion." The word is derived from the Scottish Gaelic for a "little rug," pillean, which is itself from the Latin pellis for "animal skin." One or more pelts would often have been used as a secondary seat on horseback; the usage has carried over to motorcycles.