added by archaeologs The stibadium (plural: stibadia) is a later form of the Roman lectus triclinaris, the reclining seat used by diners in the triclinium. Originally, the lecti were arranged in a group of three in a semi-circle. The stibadium was a single semi-circular couch, fitting up to a dozen people, which replaced the triple group of lecti in the dining-room, frequently in alcoves around the centre of the room.
https://en.wikipedia.org/wiki/Stibadium