Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
frĕquentātīvus, a, um, adj. [frequento], in the later gramm., that denotes the repetition of an act, frequentative: verba, Gell. 9, 6, 1; Diom. 336 P.: verborum qualitas, id. 335 P.
Adv.: frĕquentātīve, frequentatively, Fest. s. v. verberitare, p. 379 Müll.