n. The act or practice of grafting by budding.n. Hence The ingrafting of any minute germ in a soil where it will grow; especially, the act or practice of communicating disease by introducing through puncture infectious matter into the tissues; the introduction of a specific animal poison into the tissues by puncture or through contact with a wounded surface; specifically, in medicine, the direct insertion of the virus of smallpox in order, by the production of a mitigated form of it, to prevent a more severe attack of the disease in the natural way.n. Vaccination against disease, as against smallpox, anthrax, rinderpest, and to some extent against typhoid fever, plague, dysentery, etc.