the doctrine that the substance of the bread and wine of the Eucharist exists, after consecration, side by side with the substance of the body and blood of Christ but is not changed into it
See consubstantiation in American Heritage Dictionary 4
(kŏnˌsəb-stănˌshē-āˈshən)
noun
The doctrine, proposed by Martin Luther, that the substance of the body and blood of Jesus coexists with the substance of the bread and wine in the Eucharist.