Lewis & Short

plŭvĭus, a, um, adj. [pluo], rainy, causing or bringing rain, rain- (class.): SI AQVA PLVVIA NOCET, rain-water, Fragm. XII. Tab.; cf. aquae, Cic. Mur. 9, 22; id. Top. 9, 38: tempestates, Cato, R. R. 2, 3: caelum, Varr. R. R. 1, 13, 2: Hyades, rain-bringing, Verg. A. 3, 516: venti, Hor. C. 1, 17, 4: rores, rain, id. ib. 3, 3, 56: arcus, rainbow, id. A. P. 18: Juppiter, who dispenses rain, Tib. 1, 8 (7), 26 (cf.: Juppiter uvidus, Verg. G. 1, 418, and Ζεὺς ἰκμαῖος): dies, Col. 2, 15: caeli status, id. 2, 10: nomen, Plin. 2, 39, § 106.
Hence, subst.: plŭvĭum, ii, n., = impluvium, q. v., the inner court of a dwelling, Ter. Eun. 3, 5, 41.