cowpox(n = noun.state) vaccinia - a viral disease of cattle causing a mild skin disease affecting the udder; formerly used to inoculate humans against smallpox;
A pustular eruptive disease of the cow, which, when communicated to the human system, as by vaccination, protects from the smallpox; vaccinia; -- called also kinepox, cowpock, and kinepock. Dunglison. [1913 Webster]