A picture or carving (or set of three such) in three compartments side by side, the lateral ones being usually subordinate, and hinged so as to…

An altar-piece or other painting composed of two leaves which close like a book.

A painting, typically an altarpiece, consisting of more than three leaves or panels joined by hinges or folds. Cf. diptych, n., triptych, n.

An altar-piece, esp. one consisting of a group of pictures or painted panels connected by architectural structure.

A work of painting or sculpture intended to ornament the ‘gradin’ of an altar.