Wordnet 3.0
NOUN (2)
1.
a dining room (especially a dining room containing a dining table with couches along three sides);
2.
a dining table with couches along three sides in ancient Rome;
The Collaborative International Dictionary of English v.0.48:
Triclinium \Tri*clin"i*um\, n.; pl. Triclinia. [L., from Gr.
?, ?; ? (see Tri-) + ? a couch.] (Rom. Antiq.)
(a) A couch for reclining at meals, extending round three
sides of a table, and usually in three parts.
(b) A dining room furnished with such a triple couch.
[1913 Webster]
WordNet (r) 3.0 (2006):
triclinium
n 1: a dining room (especially a dining room containing a dining
table with couches along three sides)
2: a dining table with couches along three sides in ancient Rome