n. The act of transfusing, or of pouring, as a liquid, out of one vessel into another; hence, in general, transmission; transference.n. In medicine, the transmission of blood from one living animal to another, or from a human being or one of the lower animals into a human being, with the view of restoring the vigor of exhausted subjects or of replacing the blood lost by hemorrhage; also, the intravenous injection of other liquids, such as milk or saline solutions, in order to restore the circulating fluid to its normal volume, as after severe hemorrhage.