Powder barrels refer to containers used to store gunpowder. Though this term is still used today, there are several synonyms for it. One such synonym is keg, which is a small barrel used for storing liquids or powders. Another synonym is cask, which is a barrel-shaped container that can be used to store anything from liquids to food. Another alternative is a drum, which is a cylindrical container used for storing chemicals, powders, or liquids. Additionally, you can use the word canister, which refers to a metal container used to store dry goods, such as gunpowder. Whatever synonym you opt to use, it is important to understand that each of these options can help you describe a powder barrel without using the term itself.