What is another word for gas?

Another word for gas is "vapor." Vapor refers to a substance in a gaseous state at a temperature below its critical temperature, whereas gas can refer to a substance in a gaseous state at any temperature. Vapor is often used to describe substances that are typically in a liquid or solid state at room temperature, such as water vapor or vaporized chemicals. The term vapor is also commonly used in the context of vaporization or evaporation processes.