Definitions for unchurchʌnˈtʃɜrtʃ
Random House Webster's College Dictionary
to expel from a church; excommunicate.
to deprive of the character and rights of a church.
Origin of unchurch:
To expel from membership of a congregation or church; to excommunicate
to expel, or cause to separate, from a church; to excommunicate
to deprive of the character, privileges, and authority of a church