What is Vestry?

Legal Definition
A vestry was the committee for the secular and ecclesiastical government for a parish in England and Wales, which, until this was forbidden in 1850, met in the vestry or sacristy of the parish church, and consequently became known colloquially as the "vestry".
-- Wikipedia
Legal Definition
In ecclesiastical law. The place in a church where the priest's vestures are deposited. Also an assembly of the min-istor, church-wardens, and parishioners, usually held in the vestry of the church or in a building called a "vestry-hall," to act upon business of the church. Mozley & Whitley.
See also
-- Black's Law Dictionary