1. 1  a person who knowingly helps another in a crime or wrongdoing, often as a subordinate. 2  a person who helps another in committing a crime.
Fat Man and Little Boy is a 1989 film that reenacts the Manhattan Project, the secret Allied endeavor to develop the first nuclear weapons during World War II. The film is named after the weapons Little Boy and Fat Man that were detonated over Hiroshima and Nagasaki, respectively. The film was directed by Roland JoffÃ© and written by Joffe and Bruce Robinson.
 Fat Man  was the codename for the type of atomic bomb that was detonated over the Japanese city of Nagasaki by the United States on 9 August 1945.It was the second of the only two nuclear weapons ever used in warfare, the first being Little Boy, and its detonation caused the third man-made nuclear explosion.wo more Fat Man bombs were detonated during the Operation Crossroads nuclear tests at Bikini Atoll in 1946. Some 120 Fat Man units were produced between 1947 and 1949, when it was superseded by the Mark 4 nuclear bomb.