To remove the brain from something, or metaphorically, to deprive of intelligence or understanding.
From dis- (reverse/undo) + brain (from Old English 'brægen', from Proto-Germanic root meaning the brain as the soft part of the skull). A rare and archaic formation.
This word is so obscure that finding it in texts is like discovering a linguistic fossil—it shows how creative Renaissance and medieval writers were in forming verbs from any noun using the dis- prefix, even when it made little practical sense.
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