HM has various meanings in the Governmental & Military category. Discover the full forms, definitions, and usage contexts of HM in Governmental & Military.
Hazardous Material
Most Common
Any solid, liquid, or gas that can harm people, other living organisms, property, or the environment. It may be radioactive, flammable, explosive, toxic, corrosive, biohazardous, an oxidizer, an asphyxiant, a pathogen or an allergen.