a term used to express joy or excitement. You will find this word in sketch gamers' vocabulary. Should only be used over the internet and should not be found in the dictionary.
"Today i played WoW for 22 hours and i jacked off to my character, w00t." "I haven't seen daylight in 14 days, w00t"
by Jay Cash Symbol July 18, 2008
exclamation of joy, origins much-contested, but definitely pre-dating online games such as Counterstrike and Everquest- oldest usenet post containing such usage is January 08 1996. Said to originate from 133tspeak (which would pre-date that post by several years), an exclamation of 'root!'- meaning someone had achieved root-level access in a Xnix-based system, and thus, had full access.
"I'm required to enter an example! w00t!"
by Will Von Wizzlepig June 10, 2005