freem
The word "freem" is an onomatopoeia describing the sound a lascannon makes when it fires. It was first used in the Warhammer 40k themed webcomic Turn Signals on a Land Raider on February 12, 2004, as can be seen here: http://tsoalr.com/?p=58.
Example:
The freem freem of the lascannons filled the air as the massed enemy fell in droves on the battlefield.
The freem freem of the lascannons filled the air as the massed enemy fell in droves on the battlefield.