Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
sessĭto, āvi, 1, v. freq. n. [id.], to sit much or long (very rare): quam deam (Suadam) in Pericli labris scripsit Eupolis sessitavisse, * Cic. Brut. 15, 59: sessitandi regio, of the seat, of the posteriors, App. Dogm. Plat. 1, p. 10, 40.