[can.tha.ris] n, pl can.thar.i.des [ME & L; ME cantharide, fr. L cantharid-, cantharis, fr. Gk kantharid-, kantharis] (14c) 1: spanish fly 1
2. pl but sing or pl in constr: a preparation of dried beetles (as Spanish flies) used in medicine as a counterirritant and formerly as an aphrodisiac