Military organizations, like nearly all large exclusive organizations, develop slang as means of self-identification. Military slang includes phrases such as: ; Hit the silk: To abandon an aircraft mid-flight by means of a parachute. For example, "Johnson's plane took a lot of flak, but he hit the silk just in time!" ; High-speed, low drag and Teflon-coated: excellent, particularly of equipment ; Sierra Hotel: The NATO phonetic alphabet abbreviation for Shit Hot. It is considered high praise and is the pilot's favorite and all-purpose expression of approval. For example, "That Sierra Hotel pilot just shot down six MiGs and an ICBM!" This is the "polite" military way to say that something is very impressive, and has fallen into use outside the military. ; Ruptured duck: The Honorable Service award given to US service members who were discharged under honorable conditions during WWII. Also used to describe the recipient.

Military slang is also used to reinforce the (usually friendly) interservice rivalries. Some of these terms have been considered derogatory to varying degrees and attempts were made to eliminate them. Those attempts have failed because many service members take a certain perverse pleasure in the sense of shared hardship which the nickname implies. Examples of slang terms for members of the various services include: ; Jarhead: A US Marine - a reference to the "high and tight" haircut ; G.I.: A US Army soldier - This phrase is often thought to come from "General Issue". The phrase actually comes from the initials for Galvanized Iron which were stamped on the trashcans during WWII. G.I. in verb form means to clean thoroughly as in to GI the barracks. ; Grunt: A US Army soldier - sometimes, but not always, specifically refers to an infantryman ; Dogface: A US Army infantryman - common in World War II ; Doughboy: Also a US Army soldier - this term is almost exclusively used in the context of World War I ; Gun bunny: A US Army artilleryman - often specifically a cannon crewman ; Squid: A US Navy sailor ; Throttle-jockey: A jet aircraft pilot, particularly one with a penchant for speed. ; Butterbar: A Second Lieutenant in the US Army, Air Force or Marines - a reference to the insignia of rank - a single gold bar. ; The Old Man: The unit commander ; Chair Force: the US Air Force, referring to the fact that a relatively small percentage of Air Force personnel ever see combat.

Military slang has often been incorporated into the wider usage. See also: List of US Army acronyms, American English, British English