innuendo: [17] An innuendo was originally a hint given with a ‘nod’ or a wink. The word is a derivative of Latin innuere ‘signal to by means of a nod’, a compound verb formed from in- ‘towards’ and nuere ‘nod’. The ablative case of its gerund, innuendō ‘by nodding’, was used in medieval legal documents as the equivalent of ‘that is to say, i.e’. In particular, it introduced the derogatory meaning claimed by the plaintiff in a libel case to be contained in or implied by a statement, and this formed the basis for its metaphorical transference to any ‘oblique derogatory implication’. [innuendo etymology, innuendo origin, 英语词源]