from The American Heritage® Dictionary of the English Language, 4th Edition
- n. A structure forming the back of an altar, especially:
- n. An overhanging shelf for lights and ornaments.
- n. A frame enclosing painted panels.
from Wiktionary, Creative Commons Attribution/Share-Alike License
- n. A table or shelf behind an altar, on which are placed images or holy objects
from the GNU version of the Collaborative International Dictionary of English
- n. A shelf behind the altar, for display of lights, vases of flowers, etc.
from The Century Dictionary and Cyclopedia
- n. A structure raised above an altar at the back, either independent in itself, or forming a decorative frame to a picture, a bas-relief, or the like, in which case the word includes the work of art itself.
French, from Spanish retablo, from alteration of Catalan retaule, from earlier reataula, from Medieval Latin retrōtabulum : Latin retrō-, retro- + Latin tabula, tablet, board.(American Heritage® Dictionary of the English Language, Fourth Edition)
Ultimately from Latin retrotabulum (Wiktionary)