I. Lit., the blood of the sea-snail, purple (cf.: “murex, purpura): ostro Perfusae vestes,” Verg. A. 5, 111; Vitr. 7, 13.—
II. Transf.
A. Stuff dyed with purple, a purple dress, purple covering, purple: “textilibus si in picturis ostroque rubenti Jacteris,” Lucr. 2, 35: “stratoque super discumbitur ostro,” on purple-covered couches, Verg. A. 1, 700: “Sarrano dormire ostro,” id. G. 2, 506: “velare umeros ostro,” id. A. 7, 814; 4, 134; Prop. 4 (5), 3, 51. “cenae sine aulaeis et ostro,” Hor. C. 3, 29, 15; id. Ep. 1, 10, 26.—
B. The brilliancy of purple, purple, Auct. Aetnae, 332.