Lewis & Short

oecus, i, m., = οἶκος, a room in a house; a hall, saloon (only in Vitr. and Plin.): oeci magni, in quibus matresfamiliarum cum lanificis habent sessiones, Vitr. 6, 10; Plin. 36, 25, 60, § 184; cf. Becker’s Gallus, 2, p. 189 (2d ed.).