Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
vēsānĭa (vaesā-), ae, f. [vesanus], madness, insanity (very rare): extimui, ne vos ageret vesania discors, Hor. S. 2, 3, 174: simulata (Ulixis), Plin. 35, 11, 40, § 129: formidabatur flagrans vesania manus, Amm. 14, 2, 15.