gigaton

noun5

1. •
   One billion tons.
2. •
   A measure of the strength of an explosion or a bomb based on how many billion tons of TNT would be needed to produce the same energy. (A derived unit for TNT equivalent.)
3. •
   One billion short tons (10⁹ × 2000 lb).
4. •
   One billion long tons (10⁹ × 2240 lb).
5. •
   One billion metric tons (10⁹ × 2204.6 lb).