Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
pĕcūlātor, ōris, m. [peculor], an embezzler of public money, a peculator, Cic. Off. 3, 18, 73; Tac. H. 1, 53; Val. Max. 5, 3, 2; Salv. Gub. Dei, 7, 21.