The Collaborative International Dictionary
Deconsecrate \De*con"se*crate\ (d[-e]*k[o^]n"s[-e]*kr[=a]t), v. t. To deprive of sacredness; to secularize. -- De*con`se*cra"tion, n.
Wiktionary
n. 1 The undoing of consecration. desecration or defilement. 2 A ritual observing the removal from service of a sacred place, like the closing of a church.
Wikipedia
Deconsecration is the act of removing a religious blessing from something that had been previously consecrated by a minister or priest of that religion. The practice is usually performed on churches to be rendered to public ( secular) use or demolished.
Usage examples of "deconsecration".
Then the rituals of deconsecration of the cocoon had had to be carried out, so that they would not leave their souls behind on the long march to come.
St Julian's Craft Centre, much of the church edifice untouched, stalls where once there had been pews, the altar removed during the process of deconsecration.