Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
perfunctōrĭus, a, um, adj. [perfunctus; despatched, i. e.], done in a careless or superficial manner, slight, careless, negligent, perfunctory (jurid. Lat.): examinatio, Nov. Val. 3, Postul. 2, 11, c. l. § 1: genitus, Ambros. in Psa. 37, § 37.
Adv.: per-functōrĭē, slightly, carelessly, negligently, perfunctorily (late Lat.): me coepit non perfunctorie verberare, Petr. 11: facere aliquid, Cod. Th. 12, 3, 2; cf. ib. 14, 9, 1.