Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
pertĭmĕfăcĭo, fēci, factum, 3, v. a. [pertimeo-facio], to put in great fear, to frighten greatly: pertimefactus maerore animi, Pac. ap. Non. 467, 33 (Trag. Rel. p. 96 Rib.): te pertimefacto, Brut. ap. Cic. Fam. 11, 20, 2.