transubstantiation (n.)

late 14c., "change of one substance to another," from Medieval Latin trans(s)ubstantiationem (nominative trans(s)ubstantio), noun of action from trans(s)ubstantiare "to change from one substance into another," from Latin trans "across, beyond" (see trans-) + substantiare "to substantiate," from substania "substance" (see substance). Ecclesiastical sense in reference to the Eucharist first recorded 1530s.