transfusion (n.)

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," from trans "across, beyond" (see trans-) + fundere "to pour" (from nasalized form of PIE root *gheu- "to pour"). Sense of "transfering of blood from one individual to another" first recorded 1640s.