gunpowder

This term refers specifically to the chemical mixture used to ignite projectiles. While it historically denoted black powder, it is now used as a broad category for various propellants in ballistics. As a mass noun, it is treated as uncountable. It does not have a plural form in standard usage, as it describes a substance rather than individual units. To quantify it, one must use partitive phrases such as a quantity of gunpowder or a keg of gunpowder.