Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
discerptĭo, ōnis, f. [discerpo], a tearing in pieces, rending: discerptiones eorum, Vulg. 4 Esdr. 12, 32: juris humani, Liv. 41, 24, 10 Madvig. (al. dissertio).