Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
cĕrĕbrōsus, a, um, adj. [cerebrum], having a madness of the brain,hare-brained,hotbrained,passionate, Lucil. ap. Non. p. 22, 8 sq.:unus, * Hor. S. 1, 5, 21 (but Plaut. Most. 4, 2, 36, ellebosus).
Of animals: boves, Col. 2, 11, 11.