Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
persuastrix (-itrix), īcis, f. [persuasor], she that persuades, a (female) persuader. probripellecebrae et persuastrices, Plaut. Bacch. 5, 2, 47.
Collat. form persuasitrices, Mart. Cap. 5, § 514.