transubstantiation (n.)

word-forming element meaning "across, beyond, through, on the other side of, to go beyond," from Latin trans (prep.) "across, over, beyond," perhaps originally present participle of a verb *trare-, meaning "to cross," from PIE *tra-, variant of root *tere- (2) "cross over, pass through, overcome." In chemical use indicating "a compound in which two characteristic groups are situated on opposite sides of an axis of a molecule" [Flood].

"doctrine that the body and blood of Christ coeist in and with the elements of the Eucharist," 1590s, from Church Latin consubstantionem (nominative consubstantio), noun of action from past participle stem of consubstantiare, from assimilated form of com "with, together" (see con-) + substantia "being, essence, material" (see substance). Opposed to the Catholic doctrine of transubstantiation. Related: Consubstantiate.

The term consubstantiation was employed in the doctrinal controversies of the Reformation by non-Lutheran writers, to designate the Lutheran view of the Saviour's presence in the Holy Supper. The Lutheran Church, however, has never used or accepted this term to express her view, but has always and repeatedly rejected it, and the meaning it conveys, in her official declarations. [Century Dictionary]