In a first person shooter, the act of spawning in a strategic position which allows you to pwn uber nubbage. Although no one can control where they spawn, hackspawning is often a strategic advantage for the team who is lucky enough to do so. It is often favored to hackspawn close to the enemy's flag, KOTH position, etc.
d000d!!11 I was totally hackspawning on some nubs yesterday! I sp4wn3d like 3 feet from their flag! ZOMG!!!11 HACKSPAWN!!!!