SEAL

Gamers playing online shooters use SEAL to mean "slaying everyone and laughing." Most often, a player will post SEAL in chat when they are mercilessly annihilating their opponents, and LOLing as a result.

While you're most likely to encounter SEAL while playing old-school shooters (such as Quake or Unreal), you may also encounter it while playing modern shooters or other types of PvP games. It turns out, the feeling of mirth that gamers experience while wrecking their opponents transcends specific games and genres.