Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
irpex (hirpex), ĭcis, m., = ἅρπαξ, a large rake with iron teeth, used for the same purpose as our harrow (still called erpice by the Italians), Cato, R. R. 10, 2; Varr. L. L. 5, § 136 Müll.; Serv. Verg. G. 1, 95.