Definitions:

1. A bomb more powerful than an atomic bomb, that derives its explosive energy from the thermonuclear fusion reaction of hydrogen isotopes. NOUN
   • The introduction of the H-bomb into military arsenals marked a significant escalation in nuclear armament capabilities.
2. A second-generation nuclear weapon that uses nuclear fusion to generate explosive power. NOUN
   • The detonation of an H-bomb creates a mushroom cloud and releases a massive amount of energy, far surpassing that of atomic bombs.

Synonyms:

• fusion bomb
• hydrogen bomb
• thermonuclear bomb