Chief Warrant Officer in the US Army. Mostly called 'Chief' as a nickname. There are two types of Warrant Officers, 1-technical and 2-Aviator. Since the US Army only has airplanes for dog-n-pony shows, a CWO will most likely be a Black Hawk/Advanced Combat Helicopter Pilot, so show some respect. Although called an 'officer', a CWO is neither an enlisted nor an officer, they are a small breed of specialists that are very high-speed-low-drag individuals that hold their piss for no one. Most Warrants come from 'Mother-Rucker', Alabama.