- a bomb whose potency is derived from nuclear fission of atoms of fissionable material with the consequent conversion of part of their mass into energy.
- a bomb whose explosive force comes from a chain reaction based on nuclear fission in U-235 or plutonium.
- a type of bomb in which the energy is provided by nuclear fission. Uranium-235 and plutonium-239 are the isotopes most commonly used in atomic bombs
