Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
prō-terrĕo, ŭi, ĭtum, 2, to frighten or scare away, to drive away by terror, to affright, terrify (rare but class.): filium Proterruisti hinc, Ter. Heaut. 3, 1, 37: aliquem adverso equo, Verg. A. 12, 291: aliquem jaculo parmāque, Stat. Th. 2, 645: feras ardentibus facibus, App. M. 8, p. 208, 39; Plaut. Trin. 3, 2, 77: patriā pulsus atque proterritus, Cic. Rep. 1, 3, 5: tu a tuis aedibus vi atque armis proterritus, id. Caecin. 13, 37; 9, 24; 11, 31: proterritis hostibus atque in fugam conjectis, Caes. B. G. 5, 58.