Manhattan Project

American

noun

U.S. History. the unofficial designation for the U.S. War Department's secret program, organized in 1942, to explore the isolation of radioactive isotopes and the production of an atomic bomb: initial research was conducted at Columbia University in Manhattan.

Manhattan Project British

noun

(during World War II) the code name for the secret US project set up in 1942 to develop an atomic bomb

"Collins English Dictionary — Complete & Unabridged" 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Manhattan Project Cultural

The code name for the effort to develop atomic bombs (see also atomic bomb) for the United States during World War II. The first controlled nuclear reaction took place in Chicago in 1942, and by 1945, bombs had been manufactured that used this chain reaction to produce great explosive force. The project was carried out in enormous secrecy. After a test explosion in July 1945, the United States dropped atomic bombs on the Japanese cities of Hiroshima (see also Hiroshima) and Nagasaki.

Etymology

Origin of Manhattan Project

Extracted from U.S. Army Corps of Engineers Manhattan District and DSM (Development of Substitute Materials) Project

Example Sentences

Examples are provided to illustrate real-world usage of words in context. Any opinions expressed do not reflect the views of Dictionary.com.

Given the scale of Beijing’s financial and policy support and the secretive nature of some of these programs, it’s safe to say mastering fusion has become China’s Manhattan Project.

From The Wall Street Journal

In Los Alamos: The real home where Robert Oppenheimer, director of the Manhattan Project nuclear-weapon program, lived with his family was used for some interior shots in “Oppenheimer,” starring Cillian Murphy.

From The Wall Street Journal

Our universities educated Americans who directed the Manhattan Project, created a vaccine for polio and invented personal computing.

From The Wall Street Journal

The war wasn’t long over before Truman supported legislation establishing the Atomic Energy Commission to regulate nuclear technology, swallow the Manhattan Project infrastructure and take custody of America’s modest atomic arsenal.

From The Wall Street Journal

Until strategic mistakes and then the Manhattan Project’s big booms tilted the power.

From The Wall Street Journal

Definitions and idiom definitions from Dictionary.com Unabridged, based on the Random House Unabridged Dictionary, © Random House, Inc. 2023