Se-dĭl'ĭ-ŭm, n.

noun

n.; pl. SE-DĬL'I-A. [Lat.] 1. (Rom. Antiq.) One of a row of seats in the amphitheater. 2. Hence, a seat in the chancel of a church near the altar, for a priest or deacon during the eucharistic service. Hook.

An ornate medieval high-backed chair with a carved canopy and decorative panels.
Sedilium. (2.)