NOTE: NSFW; language may be offensive to some. 

Waging war is a risky, all-encompassing endeavor physically, emotionally, and psychologically. It displays humankind at its best and at its worst, and the war fighter’s slang reflects the bitter, terrible, and inspiring all of it. A quick scan of these phrases illustrates the spectrum: disciplined bravado provides the glitz and glamour; earned camaraderie, the sincerity and warmth; irony, the realist’s edge; scorn, the punishing barb; and insistent vulgarity, a rowdy,leveling earthiness. A little verbal bravado and swagger has genuine utility. Hollywood bravado is little more than chest thumping bluster, but seasoned vets know that disciplined bravado indicates confidence and courage.

Vandoo or Van Doo
(Canada) Nickname for the Royal 22e Régiment, based on the English perception of the French pronunciation for “22” (Vingt-deux); said to have lead the Germans to believe the regiment was named Voodoo Regiment during WWI or WWII.

(RN) Navigator of a private or capital ship; probably derived from Vasco da Gama.

VFR direct
(U.S. Air Force and U.S. Navy) To circumvent normal chains of communication or command; for example, “I can’t believe the butterbar went VFR direct to the Old Man!” From “Visual Flight Rules”, meaning to take the most direct route; said to also be a jocular acronym for “Visually Follow Railroads.”

(U.S. Air Force) What F-16 Pilots affectionately call the F-16 Fighting Falcon. (An allusion to the fighter from Battlestar Galactica)

(U.S., Canada) A supposedly optional event, award, assignment, or activity in which a person (or persons) are required to attend either by persons-in-charge nominating them or their peers expecting them to be there. The individual often has no say in the matter, and non-attendance is frowned upon.

WAG Fuel load
(U.S. Air Force) “Wild Ass Guess” Fuel load. Typically used by Job Control (“JC” or “Control”) with heavy transport aircraft i.e., (Lockheed C-5 “Galaxy”) to describe the estimated fuel load if none is given by flight operations (i.e., 10,000 “WAG”). The “WAG” fuel load assures the aircraft has at least the minimum fuel required to rapidly deploy if necessary.

walking mattress
(U.S.) Derogatory term used to describe a woman Marine, a.k.a. WM

Wall-to-wall counseling
(U.S.) Used to describe the assault of a subordinate in response to poor performance and/or insubordination.

waste of money
(U.S.) Derogatory term used to describe a woman Marine, a.k.a. WM

(U.S.) The A-10 Thunderbolt II.

wavy navy
(U.K. and Commonwealth) Pre-1952 referring to the naval reserve of the Royal Navy and its empire/dominion counterparts (Royal Canadian Naval Reserve, Royal Australian Naval Reserve, Royal New Zealand Naval Volunteer Reserve, etc.). Historically, the Reserve officers wore rank stripes that were wavy, denoting reserve status. from a regular Navy officer.

(Singapore) to act good in front of authority. The derivation of this term is from the Malay/Indonesian word for a shadow puppet show

Weather Guesser
(U.S. Navy) Slang for a Sailor in the AG (Aerographers Mate) rating. Weather forecasters. Self-explanatory.

(pl: Weaponettes) Pejorative term for a submarine’s Weapons Department members as used by Navy/Ops or Engineering, usually when they want their stolen tools back

weekend warrior
1. (U.S.) A National Guard member or reservist.
2. (Canada) A Canadian Armed Forces reservist
3. (U.K.) British Territorial Army- since pressed into service in overseas war zones alongside regular troops

…when “Centurion” was a rank, not a tank
A long time ago. Falling out of usage as the Soldiers who can actually remember Centurion tanks retire from service.

What the piss trainee
(U.S.) A phrase yelled by Military Training Instructors (MTIs) in the U.S. Air Force when a trainee messes up.

Whiskey Charlie
(Germany) NATO phonetic alphabet for “water-closet” (Toilet) – not used that much.

Whiskey Delta
(U.S.) NATO phonetic alphabet for “Weak Dick”. Derogatory term used to describe someone who is not up to the task.

(Australia) Waste of f***king time & money – usually refers to a useless soldier

Whiskey Locker
(U.S. Marine Corps) A closet in MCRD squad bays used to store hygiene gear and to hold private “Motivational Speeches” See thrashings.

whiskey Pete
(U.S.) White Phosphorus.

Whiskey Tango Foxtrot or WTF
(U.S., U.K.) , What the Fuck (NATO phonetic alphabet) .
1. (Canada) Coverall-like camouflage used during winter season, usually of uni-white appearance. Worn over the combat uniform, they blend in the snow.
2. Naval white dress uniform.
3. (Canada) Ceremonial white webbing and accoutrements.

(U.S. Army) Same meaning as “Hooah,” although it is considered to be the war cry of the U.S. Army Rangers.