shadow ball 

A game of catch played using an imaginary ball.

No matter how many times I played shadow ball, I could never once just catch the goddamn ball.

shadow ball by Gleasonator January 1, 2012

shadow balling 

Shadow balling is when you're on some online chat service, such as, teamspeak or ventrilo, and you silently jack off without muting yourself.

Dude you haven't said anything over teamspeak for a while. Are you shadow balling?

shadow balling by Steel Can July 10, 2016