An explosive weapon of enormous destructive power caused by the fusion of the nuclei of various hydrogen isotopes in the formation of helium nuclei.
An extremely destructive nuclear bomb in which an initial atomic bomb explosion creates the necessary intense heat and pressure to start a nuclear fusion explosion of the heavy isotopes of hydrogen (deuterium and tritium); H-bomb.
An extremely destructive bomb whose explosive power is derived from the energy released when hydrogen atoms are fused to form helium. This atomic fusion reaction is the same reaction that takes place in stars like the Sun, where the pressure of gravity forces hydrogen atoms to fuse; a hydrogen bomb uses the force of an atomic explosion (the fission reaction exploited in atomic bombs ) to compress the hydrogen to the point where fusion takes place. Hydrogen bombs are many times more powerful than atomic bombs.