Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
† attĭcisso, āre, v. n., = ἀττικίζω, to imitate the Athenian manner of speaking: hoc argumentum graecissat, tamen non atticissat, verum sicilicissitat, Plaut. Men. prol. 12; App. Flor. n. 18, p. 362, 12.