A loaded gun with ammunition or a round in the chamber of the weapon that is cocked and hammer locked (if single action) or ready to be fired by simply pulling the trigger.
Often a carry handgun with a loaded magazine that has been cocked locked and ready to rock. It is ready to fire. If a single action pistol the hammer has been cocked back and locked in place. Only the trigger must be depressed to fire the weapon.
by Steve2312002 January 25, 2009
Totally prepared and/or anticipatory for a particular engagement. Generally used in the positive sense, for an event which one looks forward to. More euphonic than similar cocked locked and ready to rock.
"Dude, you still good for that party over at Jay-Jay's?"

"Shit, nigga -- I'm locked, cocked and ready to rock!"
by EnglishMayjah February 9, 2009