transubstantiation

n. act of being transubstantiated; process of becoming something else; belief that sacred wine and bread become the body and blood of Jesus in the sacrament of the Mass (Christianity)

Transubstantiation (in Latin, transsubstantiatio) is the change of the substance of bread and wine into the Body and Blood of Christ occurring in the Eucharist according to the teaching of some Christian Churches, including the Roman Catholic Church. In Greek, it is called (see Metousiosis).
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Noun
1. the Roman Catholic doctrine that the whole substance of the bread and the wine changes into the substance of the body and blood of Christ when consecrated in the Eucharist
(hypernym) theological doctrine, religious doctrine
(derivation) transubstantiate
2. an act that changes the form or character or substance of something
(synonym) transmutation
(hypernym) conversion
(derivation) transform, transmute, transubstantiate

(n.)
The doctrine held by Roman Catholics, that the bread and wine in the Mass is converted into the body and blood of Christ; -- distinguished from consubstantiation, and impanation.
  

(n.)
A change into another substance.
  

Transubstantiation The doctrine of the Roman Catholic Church that the bread and wine of the Eucharist or Communion are miraculously transmuted into the veritable (literal) body and blood of Jesus, due to a literal interpretation of figurative language used by Jesus. It is not mere consecration of the elements -- bread and wine -- though in what the difference consists it is hard to define. See also BREAD AND WINE
The ancients had their own views about such things, as in the Bacchic rites of Greece and Rome in which bread and water or wine were considered to be mystically -- not veritable and actual -- symbols of certain of the mysteries of the divinity they revered.