To steal thoroughly or completely, or to rob someone entirely of their possessions; an archaic intensive form of 'steal.'
From 'be-' prefix plus 'steal,' where 'steal' comes from Old English 'stelan,' intensified by the prefix to suggest total or complete theft.
Medieval literature uses 'besteal' in a way that's almost humorous—it suggests such thorough stealing that nothing is left, creating an image of complete destitution that's more vivid than just 'rob' or 'steal.'
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