Navy slang for a person engulfed in flames, usually running around screaming; so termed because burning people fit into the category of class-A/class-Alpha fires (those involving solid, organic combustibles and which leave ashes).
"If you watch that news film of the Hindenburg crash, you can see a bunch of screaming alphas come running out of the wreckage."
Playing a training game against another clan/team in a computer game.
Me: Hey progamer that I can bother about anything because of steam, wanna play a game?
Pro: fu noob Im scrimming
Me: Oh whats that?
pro: stop msgs its annoying Me: Oh really? how annoying?