An armor perk in Halo: Reach that is used by 6 year old n00bs who took their dad's copy of the game off of the top shelf and are soon to be beat with a belt because of it. They use it during Matchmaking Games because they've pissed their pants out of fear and are too scared to mindlessly spam grenades or spray with the assault rifle.
If you use armor lock throughout an entire match and at the end the screen tells you that you won, this is most likely an error and you should not take it too seriously. Because if you used armor lock, you didn't win anything and you fucking suck.
Real Player (Only Using Sprint): *Throws A Plasma Grenade* "Good I got a kill. (assuming that the enemy will die)"
Retarded Player: *Turns On Armor Lock, Sticky Falls Off* "Too..scared.. to use..any other...shitty maneuvers."
*Everyone Else Crowds Around Retard Player, Waiting For Him/Her To Stop Being A Pussy. Whoever Survives The Massive Close-Range Firefight After Gets To Teabag The Armor Locker.*