Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
cūrĭōsĭtas, ātis, f. [curiosus], desire of knowledge, curiosity, inquisitiveness (very rare), Cic. Att. 2, 12, 2; Macr. S. 1, 11, 45; Tert. adv. Haeret. 17; id. Apol. 25.