Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
perfector, ōris, m. [perficio], a finisher, perfecter (rare but class.): mearum voluptatum, Ter. Eun. 5, 8, 4: dicendi, Cic. de Or. 1, 60, 257; Scip. ap. Cic. Att. 8, 11, 1.