Triclinium

[1] The word is adopted from the Greek triklinion (τρικλίνιον)—from tri- (τρι-), "three", and klinē (κλίνη), a sort of couch, or rather chaise longue.

Each couch was sized to accommodate a diner who reclined on their left side on cushions while some household slaves served multiple courses brought from the culina, or kitchen, and others entertained guests with music, song, or dance.

The custom of using klinai ("dining couches") while taking a meal rather than sitting became popular among the Greeks in the early seventh century BC.

Typically, nine to twenty guests were invited, arranged in a prescribed seating order to emphasize divisions in status and relative closeness to the dominus.

[3] As static, privileged space, dining rooms received extremely elaborate decoration, with complex perspective scenes and central paintings (or, here, mosaics).

In later republican times, after the introduction of round tables of citrus wood, the three couches were replaced by one of crescent shape (called sigma from the form of the Greek letter), which as a rule was only intended to hold five persons.