Emphasizing something to all srsly large possibilities. Literally speaking, your level of disgust/amazement/horniness is officially "over 9000".
ALSO: A state of mind in which you are unbannable from the shoutbox, causing you TO TYPE IN ALL CAPITALS IN FRONT OF MODZ.
"Dude I just saw my mom naked and I totally capsed."
"OMFG DOOD UR SERBA IS LEET U MADE ME CAPS."
"Lol srs business shoutbox stop capsing."