Governments, businesses, clubs, and charities all have treasurers to manage their money. If you volunteer to be the treasurer of your school French club, you'll be responsible for keeping track of the money that comes in from your bake sale, as well as what's spent on your trip to Quebec. The noun treasurer comes from the Old French word for "treasure," tresor, which has its ultimate root in the Greek word thesauros, "store, treasure, or treasure house."