Origin: 1250–1300; Middle English ranclen < Middle French rancler,Old French raoncler, variant of draoncler to fester, derivative of draoncle a sore < Late Latin dracunculus small serpent, diminutive of Latin dracō serpent; see dragon, carbuncle
c.1320, from O.Fr. rancler, from draoncle "abscess, festering sore," from L. dracunculus "little snake," dim. of draco (gen. draconis) "serpent, dragon." The notion is of an ulcer caused by a snake's bite.