Parsing inflected forms may not always work as expected. If the following does not give the correct word, try Latin Words or Perseus.
ex-cĕrē̆bro, āre [cerebrum], to deprive of brains, i. q. to make senseless: canem, Vulg. Isa. 66, 3.
Part.: ex-cerē̆brā-tus, a, um, deprived of brains, i. q. rendered senseless, stupefied: excerebratus es novo vino, Tert. adv. Marc. 4, 11.