poison gas -
a gas that is poisonous to breath or contact; used in chemical warfare
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
chemical weapon chemical substances that can be delivered using munitions and dispersal devices to cause death or severe harm to people and animals and plants
