A JV Stock comes from Super Smash Bros. If the game ends and you are at 0%, it will be a JV(number of stocks you have plus 1) Stock. It is used often by people who play the game.
Remember, a JV Stock is what occurs when you are at 0% at the end of a game.
"I lost a stock, but at least I got the JV."
"JV4'd your ass!"
"At least I got the JV."
"That was a JV4 because I had 3 stocks and took no damage."
"Will they get the JV?"
Clutchbox is a nickname given to Juan "Hungrybox" DeBiedma due to his pension for ridiculous comebacks in Super Smash Bros games. These "Clutch" displays happen more often than one would expect.