Lewis Short
cēnācŭlum | caen- | coen- (noun N) : ( and ), , cena, orig.
* A dining-room, usu. in an upper story; hence, an upper story, an upper room, a garret, attic (later, the dwelling of the poorer class of people): ubi cubabant cubiculum, ubi cenabant cenaculum vocitabant. Posteaquam in superiore parte cenitare coeperunt, superioris domūs universa cenacula dicta,Varr. L. L. 5, § 162 Müll.: cenacula dicuntur, ad quae scalis ascenditur (the Gr. ὑπερῶ̔ον), Paul. ex Fest. p. 54, 6 ib.; cf. Liv 39, 14; Cic. Agr 2, 35, 96; Vitr. 2, 8, 17; Quint. 6, 3, 64; Suet. Aug. 45; 78; Hor. Ep. 1, 1, 91; Juv. 10, 18; Suet. Vit. 7; Dig. 7, 1, 13, § 8; 8, 2, 41 pr.; 9, 3, 5, § 9; Inscr. Orell. 4323 sq.
* Transf, like ὑπερῶ̔ον: maxima caeli, Enn. ap. Tert. adv. Val. 7 (Ann. v. 61 Vahl.); cf. in Plaut. humorously of the abode of Jupiter: in superiore qui habito cenaculo, Plaut Am. 3, 1, 3.
Charlton T. Lewis, Charles Short, A Latin Dictionary