A sortie (from the French word meaning exit or from Latin root surgere meaning to "rise up") is a deployment or dispatch of one military unit, be it an aircraft, ship, or troops, from a strongpoint.
Another popular meme from the games is the now-infamous Ghost stare, which came from Call of Duty: Modern Warfare 2's campaign, wherein people used the stare Ghost gave to Soap MacTavish as a reaction (of varying degrees) to everyday situations.