A phrase used in the videogame Modern Warfare 2
that instructs a teammate to go out of their way to make the last kill of a search and destroy round awesome so that everyone will be able to see it in the killcam.
The phrase "Make it Dirty" can be used in any gametype, but if it isn't the round winning kill, no one will be able to see your Dirtyness.
person 1: "Ok there's only one guy left, Make it Dirty"
person 2 sees the last player hiding behind a car and can easily snipe him, but instead runs up to the car, climbs on top of it and jumps off right in front of the enemy and shoots his head off mid air with his pistol.
guy3: "That was so dirty"