predella

/prɪˈdɛlə/
noun
  1. A painted or sculpted panel, or a series of panels, forming the lower part of an altarpiece, often depicting scenes related to the main subject.
    • The altarpiece's predella shows scenes from the life of Saint Francis.
    • The museum displayed the predella separately from the main altarpiece to allow closer viewing.
    • Art historians carefully restored the predella, which had been damaged over centuries.