The Church of Ireland – within each Parish – have elections each year to elect representatives who are like a board of guardians – making decisions on church matters.
From the book “Second edition. Aid to The Book of Common Prayer – Its Origin and History and other information concerning the services of the Church” by Richard A. Rogers — the definition is given of “Vestry” as
A room for “vesting”; in; a body of men selected from the parishioners.