Megaton

n. one million tons, explosive force equal to a million tons of TNT (especially referring to an atom or hydrogen bomb)

TNT equivalent is a method of quantifying the energy released in explosions. The tonne of TNT is used as a unit of energy, approximately equivalent to the energy released in the detonation of this amount of TNT.The kiloton and megaton of TNT have traditionally been used to rate the energy output, and hence destructive power, of nuclear weapons (see nuclear weapon yield). This unit is written into various nuclear weapon control treaties, and gives a sense of destructiveness as compared with ordinary explosives, like TNT. More recently, it has been used to describe the energy released in other highly destructive events, such as asteroid impacts.
See more at Wikipedia.org...

Noun
1. a measure of explosive power (of an atomic weapon) equal to that of one million tons of TNT
(hypernym) explosive unit
2. one million tons
(hypernym) avoirdupois unit
(part-meronym) kiloton

n. megaton, one million tons, explosive force equal to a million tons of TNT (especially referring to an atom or hydrogen bomb)

n. megaton, one million tons