- mass and energy considered as equivalent and interconvertible, according to the theory of relativity
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012
Examples from the Web for mass-energy
"Take that carrion and stuff it in a mass-energy converter," he said.Space Viking
Henry Beam Piper
There was a collapsium plant, with its own mass-energy converter.
This was in line with familiar twentieth-century concepts of mass-energy transformation.The Variable Man
Philip K. Dick
Remember those big wire baskets, down at the mass-energy converters?
In the first place, there's a full-sized power-reactor, and a mass-energy converter.