Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
stŏlĭdĭtas, ātis, f. [stolidus], dulness, obtuseness, stupidity, stolidity (post-class.), Flor. 3, 3, 12; 4, 12, 16; Gell. 18, 4, 6; Arn. 2, 80 al.