a term given —
1. To a portable altar, placed on the altar itself at the time of the celebration of the Christian Eucharist, or set up separately. Hincmar (867) allowed the use of a consecrated site, marble, or a black stone slab, probably owing to the needs of the Crusaders and the deficiency of churches. It was large enough to contain the chalice and host. (See ALTAR, PORTABLE).
2. Ordinarily and commonly this term is applied to the ledge behind the altar, on which relics, flowers, candlesticks, and the altar-cross stand. It is very frequently so applied in the ancient Church of England.