tri·clin·i·um 
(trī-klĭnē-əm)
(trī-klĭnē-əm)n. pl. tri·clin·i·a (-ē-ə)
1. A couch facing three sides of a rectangular table, used by the ancient Greeks, Etruscans, and Romans for reclining at meals.
2. A room containing such a couch or couches; a dining room.
[Latin trīclīnium, from Greek triklīnion, diminutive of triklīnos, room with three couches : tri-, three; see trei- in the Appendix of Indo-European roots + klīnē, couch; see klei- in the Appendix of Indo-European roots.]