1. A location in a church or religious building in which the vessels, clothing, etc. used for church services are kept: A member of a congregation always goes to his or her house of worship each weekend to be sure everything in the sacristy is clean and in order before the services begin.
2. Etymology: "a repository of sacred things" from about 1600, from Anglo-French sacrestie, from Middle Latin sacrista; which came from Latin sacer, "sacred".