In videogame folklore, when an announcement is due to be made that will "shake the foundations of gaming to its core", it is referred to as the "megaton". It inevitably turns out to be completely lame and non-eventful. Like perhaps a competition to go to some Xbox360 party in the US by yourself.

Any weapon equal to one million tons of dynamite. 1 megaton = 1,000,000 tons, 4 megatons = 4,000,000 tons.

When something is so retarded and stupid (ex. Dating an ugly girl) you refer to it as "Blowin' Up Megaton" from the Xbox360, PS3 and PC game Fallout 3 created by Bethesda. Usually only people who have played Fallout3 would recognize the use of this word. An explosion so epic, when seen at the Balcony of Tenpenny Tower at night time, you notice you've made a big mistake. But hey, YOU GOT 500 CAPS FREE! :")

A person who is incredably overweight thus being more than a ton. A MEGAton. These people tend to play Halo Pc and rage quit 7 times during a 1v1 match. They also upload themselves with a red smuded 7 in the upper left hand corner. Then he will talk shit and Sasuke will pass down the torch of hatedness to Megaton and he will continue the legend of Halo fags.

A codename for future online gaming link software that connects through a small little box, to a cheap, donated, server, to another box. A future sign would be a green ppe with a green square on top with some sort of oppening to transport from one place to another.