Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
prĕcātus, ūs, m. [precor], a prayer, request (poet, and post-class.), Stat. Th. 10, 71: concordi precatu tentare aliquid, Amm. 24, 6, 5: dabitur precatui tuo, Sid. Ep. 8, 15: precatibus efficacissimis obtinere, id. ib. 9, 3.