The Collaborative International Dictionary
Nuclear device \Nu"cle*ar dev"ice\, n. an explosive device, whether used as a weapon or for other purposes, which depends for most of its explosive power on the release of energy from within atomic nuclei. A fission device or a fusion device.
Usage examples of "fusion device".
That means a third-generation fission weapon, or more likely, a multi-stage fusion device.
The bad news is that the explosive power of a relatively small, pure-fusion device would be much greater than even our most modern hydrogen bomb.
And only massive jolts of energy, such as a fusion device or a massive particle beam, seemed to affect them.
That's on the order of a trillion times our most powerful fusion device.
It is a tactical fusion device with an antimatter trigger, small but highly sophisticated, more a puzzlement than a threat.
The new atomic pile improvement was an automatically controlled fusion device producing 500 kilowatts per hour.