Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
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.