Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
prōscriptŭrĭo, īre, v. desider. n [id], to desire or long to proscribe, (a word formed sarcastically by Cic.): ita sullaturit animus ejus et proscripturit diu, Cic. Att. 9, 10, 6 (cited Quint. 8, 6, 32).