dossal

thumb|The "Bardi Dossal" in the Bardi Chapel of Santa Croce, Florence. This is usually so called, but is an [[altarpiece and might also be called a retable or reredos. The shelf it rises from is a gradine.]] thumb|Dossal curtain, below a painted altarpiece, Weston-on-the-Green, Oxfordshire thumb|Green riddel curtains, with a metalwork dossal, in the Mass of St Gilles by the Master of Saint Giles

A dossal (or dossel, dorsel, dosel), from French dos (back), is one of a number of terms for something rising from the back of a church altar. In modern usage, it primarily refers to cloth hangings but it can also denote a board, often carved or containing a painting, that rises vertically from the back of the altar and to which the cloth is attached. Retable and reredos are alternative terms for solid structures, as is altarpiece, all of them rather more commonly used today.