Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
prĕcātīvē, adv., v. precativus fin.
prĕcātīvus, a, um, adj. [precor], prayed for, obtained by entreaty (postclass.): pax, Amm. 17, 5, 1: precativo modo, by prayer or entreaty, Ulp. Reg. tit. 24.
Adv.: prĕcātīvē, by request, by entreaty (post-class.), Ulp. Reg. tit. 25, 1 al.