种牛痘 zhòngniúdòu to vaccinate against smallpox Origin Definitions Defs Strokes Stroke Words Sentences Sents 种 種 zhòng verb to vaccinate to vaccinate; to inoculate; to inject a vaccine into the body to prevent disease牛痘 niúdòu cowpox an infectious disease found in cattle that is similar to smallpox; also refers to the pustules caused by this disease