The act of freaking out in a chat room (i.e. screaming). Often identifed by the keyboard use of ALL CAPS and multiple exclamation points.
I don't know who this Joey269 dude is, but he started capping out on me when I said something about his mother.
by RV2PHX April 23, 2009
cap me out means, for example, i told my buddy to lie to my girlfriend and tell her im going to the store to get groceries but im really tryna get sum pussy so i told my boy to cover for me but he said hell nah he gettin pussy