n. a bomb of great power in which the explosive energy is derived from the nuclear fission of a fissionable material, such as plutonium or uranium-235. It is a type of nuclear weapon. The strength of an atom bomb is measured in kilotons, i.e. the equivalent energy released by explosion of a thousand tons of TNT. The first atomic bomb was manufactured in 1945. Syn. -- A-bomb, fission bomb. [ PJC ]
(n) a nuclear weapon in which enormous energy is released by nuclear fission (splitting the nuclei of a heavy element like uranium 235 or plutonium 239), Syn. plutonium bomb, atomic bomb, A-bomb, fission bomb