Transubstantiation – Transubstantiation (Latin: transsubstantiatio; Greek: μετουσίωσις metousiosis) is, according to the teachings of the Roman Catholic Church, the change of substance or essence by which the bread and wine offered in the sacrifice of the sacrament of the Eucharist during the Mass, become, in reality, the body and blood of Jesus Christ.

Transubstantiation – Wikipedia

https://en.wikipedia.org/wiki/Transubstantiation

Transubstantiation (Latin: transsubstantiatio; Greek: μετουσίωσις metousiosis) is, according to the teachings of the Roman Catholic Church, the change of substance or essence by which the bread and wine offered in the sacrifice of the sacrament of the Eucharist during the Mass, become, in reality, the body and blood of Jesus Christ.