Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
spurcĭtĭa, ae (nom. collat. form spur-cĭtĭes, Lucr. 6, 977; abl. spurcitie, App. M. 8, p. 214, 33), f. [spurcus], filth, dirt, smut, dung (rare; not in Cic.).