From Longman Dictionary of Contemporary Englishmegatonmeg‧a‧ton /ˈmeɡətʌn/ noun [countable] TMPMWa unit for measuring the power of an explosive, equal to the power of one million tons of TNT (=a powerful explosive) a five megaton atomic bomb
Examples from the Corpus
megaton• The third largest event in this run, the 27 megaton blast, occurs about every seven hundred years.• The Western hemisphere would soon be in range of and vulnerable to Soviet intercontinental ballistic missiles, carrying megaton warheads.• Each contained fifteen megatons of high explosive.• Explosive energies in the kiloton to megaton range are possible.• From inside the car came the deep bass rumble of a two megaton audio system.• Even if it were only a dozen, they could with megaton bombs inflict widespread devastation.megaton ... bomb• If a 20 Megaton bomb were used today the damage would be incalculable. 