In the fold where the scrotum meets the inner thigh lies a secure place to put contraband (drugs, money, ID, etc...). Similar to a wallet/billfold the scrotum and inner thigh hold items snugly due to the fold or crease.
Can I use your bathroom quick, I need to grab somethin' outta my ballfold.
Damn, did you see how dude was walking; definitely put too much in his ballfold.
Hey, did you have this in your ballfold? It reeks like balls!
The act of sitting in a chair and nodding in and out of sleep with your upper body going up and down towards table in a bill fold like manner. This is usually caused by being extremely tired and or very high/intoxicated.
Tell your sister to move her plate of spaghetti. Her face is about to go in her food from her billfolding again. Will you please wake up and quit billfolding on the coffee table again please.