Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
tālĭo, ōnis, f. (masc., Tert. adv. Marc. 4, 16) [talis]; in jurid. lang., a punishment similar and equal to the injury sustained, like for like, retaliation in kind: talionis mentionem fieri in XII. ait Verrius hoc modo: si membrum rupit, ni cum eo pacit, talio esto, neque id, quid significet, indicat, puto, quia notum est. Permittit enim lex parem vindictam, Fest. p. 363 Müll.; Cato ap. Prisc. p. 710 P.; Gell. 20, 1, 33 sq.; 20, 1, 38; Cic. ap. Aug. Civ. Dei, 21, 11; Plin. 7, 54, 55, § 187; Tert. adv. Marc. 4, 16: corrumpit sine talione caelebs, i. e. with impunity, Mart. 12, 63, 10.