1. a tough guy, a superstar. Basically used to refer either ironically or jokingly to one of your boys. 2. Alternately may be used to refer to a guy whose name you forgot.
1. "Hey chieftain, are we going to the game saturday or what?" 2. guy: "Larry, hey, remember, we met at that wedding last summer?!" you: hey chieftain, good to see you. Let's catch up soon."
These are the leaders of brute packs in the halo games, mostly halo 3. they are seen with enormous crowns, thick black armor,and a huge gravity hammer than can send you flying. they usually charge at you, using their invincibility perk, and unless you have some sort of miracle plan, they will kill you almost instantly.