A curator was somebody who oversaw an exhibit.
In 2269, Spock responded to Lieutenant commander Tom Markel's comments about the Lactrans' reluctance to allow them to escape by saying it was a natural reaction for the curators of a zoo. (TAS: "The Eye of the Beholder")
In 2404, a retired Kathryn Janeway told the curator of the museum that if he wanted the ready room of the USS Voyager exhibit to look more authentic, there should always be a steaming pot of coffee on the desk. (VOY: "Endgame")