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2.
Also knows as as set of Bolt Cutters. Looks like a giant set of wire cutters. Can cut through nearly any pad lock.
When Ray lost the keys to the tool boxes we had to go looking for our Master Key.
by Sega Slayer March 16, 2004
 
1.
a drink that is a mixture of red wine and orange soda
i was sippin on that master key last night. It opens all the doors.
by themasterkey December 29, 2010
 
3.
A door-breaching shotgun manufactured as a custom part by Knight's Armament Company. Can be mounted under the barrel on a M4 or M16 assault rifle, like a M203 grenade launcher.
The Masterkey project was initiated during the 1980s to provide assault rifles with a potent built-in door breaching tool.
by Kaiveran October 05, 2008
 
4.
The Masterkey is a combination weapon featuring an M4 attached to a Winchester 12 gauge shotgun. It is named Masterkey for its common use as a door remover.
Have a locked door? Not anymore.
by Detranova July 29, 2003
 
5.
A shotgun used to blow-open locked doors.
The front man in the stack shot both hinges with the master key. The next guy hit the door with a battering ram.
by GewehrWolf April 03, 2007