A disgruntled and cynical person, usually a gamer roaming the forums and internet proclaiming the coming death of a certain game - usually following a controversial game update/patch.
Matt: So Dave, how do you like the new Clash of Clans update?
Dave: They really screwed over the casual player by destroying farming. I think they have about one month to fix things or all casuals will leave and the game will for sure die.
Matt: You're such a doomsayer, Dave.
Synonym for the Universidad del Museo Social Argentino, or UMSA, a university in Buenos Aires, Argentina. Due to its striking resemblance to the gates of hell and the absurdity of its 3 hour classes, the term doomsa was coined.