牛痘 niúdòu cowpox Origin Definitions Defs Strokes Stroke Words Sentences Sents niúdòu cowpox 牛 niú noun ox ox; cow; bull; cattle; any of various bovine animals痘 dòu smallpox (bound form) smallpox; a highly contagious disease caused by the variola virusniúdòu smallpox vaccine 牛 niú noun ox ox; cow; bull; cattle; any of various bovine animals痘 dòu vaccine (bound form) cowpox or the vaccine used to prevent smallpox