Definition of pentaptych in US English:

pentaptych

noun

rare
  • A painted or carved altarpiece, etc., consisting of five hinged panels (usually a central piece and two folding pieces on each side).

Origin

Mid 19th century; earliest use found in Frederick William Fairholt (d. 1866), artist and antiquary. From penta- + ancient Greek πτυχή fold (of unknown origin), after diptych, triptych.

Pronunciation

pentaptych

/ˈpɛntəptɪk/