transfusion (n.) Look up transfusion at
1570s, "action of pouring liquid from one vessel to another," from Middle French transfusion and directly from Latin transfusionem (nominative transfusio) "a decanting, intermingling," noun of action from past participle stem of transfundere "pour from one container to another" (see transfuse). Sense of "transfering of blood from one individual to another" first recorded 1640s.