Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
prŏtervĭtas, ātis, f. [protervus], pertness, sauciness, boldness, impudence (class.): protervitas levior est quaedam contumelia, procacitas major, petulantia maxima, Don. Ter. Heaut. 4, 6, 10: coërcere protervitatem, Pac. ap. Non. 121, 15 (protervitates, acc. to Fest. s. v. redhostire, p. 270 Müll.); Ter. Heaut. 4, 6, 10; Cic. Cael. 12, 29: urit me Glycerae nitor, Urit grata protervitas, forwardness, wantonness, Hor. C. 1, 19, 7.