Weapon of mass destruction (WMD) is a term used to describe a munition with the capacity to indiscriminately kill large numbers of living beings.
The phrase broadly encompasses several areas of weapon synthesis, including nuclear, biological, chemical and, increasingly, radiological weapons.
The term first arose in 1937 in reference to the mass destruction of Guernica, Spain, by aerial bombardment.
Following the bombing of Hiroshima and Nagasaki, and progressing through the Cold War, the term came to refer more to non-conventional weapons.
The phrase entered popular usage in relation to the U.S.-led 2003 invasion of Iraq.
Terms used in a military context include atomic, biological, and chemical warfare (ABC warfare), nuclear, biological, and chemical (NBC) after the invention of the hydrogen bomb, and chemical, biological, radiological, and nuclear (CBRN), recognizing the threat of non-explosive radiological weapons.