A weapon of mass destruction (WMD) is a nuclear, radiological, chemical, biological, or any other weapon that can kill and bring significant harm to numerous humans or cause great damage to human-made structures (e.g., buildings), natural structures (e.g., mountains), or the biosphere. The scope and usage of the term has evolved and been disputed, often signifying more politically than technically. Originally coined in reference to aerial bombing with chemical explosives during World War II, it has later come to refer to of other technologies, such as chemical, biological, radiological, or nuclear warfare.