Lewis & Short

sex (also written VI., and in inscrr. SEXS; cf. Inscr. Orell. 3745), num. adj. [cf. Sanscr. shash, Gr. ἕξ, Goth. saihs, Germ. sechs, Engl. six], six: sex minae, Plaut. Capt. 5, 2, 21: dies, id. Cist. 2, 1, 13: menses, Ter. Eun. 2, 2, 46; id. Ad. 3, 3, 42: sex aut septem loca, Lucr. 4, 577: suffragia, Cic. Rep. 2, 22, 39: sex et nonaginta, id. ib.: sex et quinquaginta milia passuum, id. Rosc. Am. 7, 19: decem et sex milia peditum armati, Liv. 37, 40: inter Bis sex famulas (= duodecim), Ov. M. 4, 220; Verg. A. 9, 272: sex septem, six or seven, Ter. Eun. 2, 3, 41; Hor. Ep. 1, 1, 58; v. septem, sex primi, sexprimi.