mid-13c., from Anglo-French deis, Old French dais "table, platform," from Latin discus "disk-shaped object," also, by medieval times, "table," from Greek diskos "quoit, disk, dish." Died out in English c.1600, preserved in Scotland, revived 19c. by antiquarians.
any raised platform in a room, used primarily for ceremonial purposes. Originally the term referred to a raised portion of the floor at the end of a medieval hall, where the lord of the mansion dined with his family and friends at the high table, apart from the retainers and servants. A deep-recessed bay window usually placed at one or both ends of the dais provided greater privacy for the diners than the open hall could afford. In France the word is understood as a canopy over a seat