"Woot" (w00t, wewt) was a term used for the phrase "We owned the other team!". However, it is more commonly used as a sign of happyness. Read below.
Used as an interjection, this word was originated back in the early days of MMO's and games with Online
PvP (player vs Player) action. Teams of players (
Guilds,
Clans, etc.) would go around and fight other players. When and if they would win they would all say "woot" jump around and celebrate.
However that term is now obsolete. The way it is more commonly used is still as an interjection, but it now stands for "Awsome!" or "Yay!". This may happen when something good happens to a player such as getting good
loot or leveling up in a game such as
World of Warcraft or
MU.