Transfusion

The act of transfusing, or pouring, as liquor, out of one vessel into another.

The act or operation of transferring the blood of one man or animal into the vascular system of another; also, the introduction of any fluid into the blood vessels, or into a cavity of the body from which it can readily be adsorbed into the vessels; intrafusion; as, the peritoneal transfusion of milk.

the introduction of blood or blood plasma into a vein or artery