Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
hĕbĕtūdo, ĭnis, f. [hebeto], bluntness, dulness (post-class.; cf. hebetatio): sensuum, Macr. Somn. Scip. 1, 14: superba istorum, Aug. Civ. D. 7, 21.