Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
exclūsĭo, ōnis, f. [excludo], a shutting out, exclusion (very rare; not in Cic.): de exclusione verbum nullum, Ter. Eun. 1, 2, 8: ventorum, Vitr. 1, 6: exceptio est quasi quaedam exclusio, etc., Dig. 44, 1, 2.