A condition caused by addiction to an MMORPG such as World of Warcraft. Symptoms include lack of social activity, aversion to sunlight, and endless banter about the MMORPG to people who have no clue what you're talking about.
"Dude, have you seen John in the last month?"
"No, not since he started playing Guild Wars."
"Sounds like a bad case of WoW syndrome."