(n.) A heavily armed and well-trained soldier. See rambo
Rambo is the one man army! Watch him kill 775956957594945.5 people with a handgun and two clips!
by Kung-Fu Jesus May 11, 2004
1 more definition
A perk in Modern Warfare 2. It allows you to change between classes at any time in the match. This perk replaces the player's secondary weapon. Usually frowned upon in online matches.
Damn it! I just got shot down by a n00b with One Man Army.
by MW2 Freak January 04, 2011