Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
vībex (vībix), īcis, f., the mark of a blow or stripe, a weal, Plaut. Fragm. ap. Varr. L. L. 7, § 63 Müll.; Cato ap. Non. p. 187, 26; Plin. 30, 13, 39, § 118; Pers. 4, 48; App. M. 9, p. 222, 26; cf. Fest. p. 369 Müll.