Blockbuster

(n.) anything particularly large or successful of its type

These days, when a film fails to earn its money back at the box office, we’re told that it’s ‘bombed’. But when a film turns out to be a blockbuster success, it’s quite literally a bomb—and the reason why takes us back to wartime Great Britain.

At the height of the Second World War, Britain’s Royal Air Force began developing a new design for an enormous aerial bomb, designated the high-capacity or HC bomb. Built with a thinner-than-normal outer casing, intended to leave as much room inside as possible for explosive material, the HCs were designed to be larger and more powerful than any other bomb yet employed by the British military.

After months of development, the first HC emerged in 1941: nine foot long and made of half a ton of steel, it weighed 4,000 pounds, a staggering three-quarters of which was pure explosive Amatol.

On 31 March 1941, the first of these 4,000-pound bombs was dropped in an air raid on the city of Emden in northwest Germany (one of the pilots involved in the raid later described how “whole houses took to the air”), but as the war intensified, the Air Force continued to produce larger and ever more powerful HCs.

In 1942, an 8,000-pound bomb was developed, followed by a 12,000-pound bomb the following year, which was first used in a devastating attack on the Dortmund-Ems Canal on 15 September 1943. By the end of the war, more than 120,000 HCs had been dropped on German targets, containing between them a total of a quarter of a million tons of explosive material.

To Britain’s pilots, these enormous bombs were unassumingly nicknamed cookies. To the Germans, they were the Bezirkbomben or “district bombs”. And to the English-speaking press, they were blockbusters—bombs so extraordinarily powerful that they could literally destroy an entire block of buildings:

Berlin was attacked by an all-Lancaster force that had to battle through ice and cloud to the hidden target . . . As the ‘block-busters’ fell, fires glowed over a wide area. Series of violent explosions burst through the clouds even when the bomb flashes were hidden.

The Daily Mail, 20 November 1943

The name blockbuster is thought to have been coined by American war reporters, but its use quickly caught on elsewhere. By the mid 1940s, it had been picked up by journalists on both sides of the Atlantic and had slipped into wider use: soon anything of great size, impact, success or significance—from political speeches to Broadway stage shows and bestselling novels—was being labeled a blockbuster.

Understandably, the word’s military connotations steadily dwindled and eventually disappeared after the War, leaving this figurative meaning to take its permanent place in the language.