IPA: /ˈsækrɪstən/
KK: /ˈsækrɪstən/
A person responsible for the care and maintenance of a church's sacred objects and the sacristy, which is the room where these items are kept.
The sacristan prepared the altar for the Sunday service.
Sacristan → It is formed from "sacrista" (from Latin *sacrista*, meaning a keeper of sacred things) and the suffix "-an" (meaning a person who). A sacristan is a person who takes care of the sacred objects and the sacristy in a church.
Think of a person who is a 'keeper' of 'sacred things' — that's what a sacristan does.