gas

the state of matter distinguished from the solid and liquid states by: relatively low density and viscosity; relatively great expansion and contraction with changes in pressure and temperature; the ability to diffuse readily; and the spontaneous tendency to become distributed uniformly throughout any container

a fluid in the gaseous state having neither independent shape nor volume and being able to expand indefinitely

a volatile flammable mixture of hydrocarbons (hexane and heptane and octane etc.) derived from petroleum; used mainly as a fuel in internal combustion engines

a state of excessive gas in the alimentary canal

a pedal that controls the throttle valve

he stepped on the gas