"frame of wood erected on a post or pole with holes into which were put the head and hands of an offender who was thus exposed for public derision and abuse," mid-14c., pillorie (attested in Anglo-Latin from late 12c., in surnames from mid-13c.), from Old French pilori "pillory" (mid-12c.), which is related to Medieval Latin pilloria, but all are of uncertain origin. Perhaps a diminutive of Latin pila "pillar, stone barrier" (see pillar), but OED finds this proposed derivation "phonologically unsuitable."