A backronym or bacronym is a reverse acronym, that is, the words of the expanded term were chosen to fit the letters of the acronym. The word "backronym" is a portmanteau of back and acronym and was formed by 1983.
Some backronyms are back-formed from an existing acronym by creating a new expanded term for the initials when the original term becomes inaccurate. "DVD", for example, was originally an acronym for "digital video disc"; when it was realised that a DVD could be used for non-video applications, the term "digital versatile disc" was invented (although it did not become official).
Other backronyms are back-formed from an existing word that was not previously an acronym. Generally these backronyms are apronyms, as the word used as the backronym is relevant to the expanded term it stands for. The relevance may be either serious or ironic. Most apronyms are examples of backronyms. Many jocular (and often also derogatory) apronyms are created as a form of wordplay.
Ahimsa is a religious concept which advocates non-violence and a respect for all life; it is Sanskrit for avoidance of himsa. Himsa is injury to sentient beings. It is commonly backronymed as "Abstinence from animal products, Harmlessness with reverence for life, Integrity of thought, word, and deed, Mastery over oneself, Service to humanity, nature, and creation, and Advancement of understanding and truth".
Apgar - a brief medical examination of new-born babies - was named after the doctor who introduced it but can be understood as an acronym for Appearance (skin color), Pulse (heart rate), Grimace (reflex irritability), Activity (muscle tone), Respiration.
Fuck - urban legends often give this obscenity a backronymic folk-etymology such as Fornication Under Consent of the King, Found Under Carnal Knowledge, For Unlawful Carnal Knowledge, or Fornication Unlawful in the Commonwealth of the King. [1] (http://www.snopes2.com/language/acronyms/fuck.htm)
Golf - a popular urban legend states that the game of golf originally stood for Gentlemen Only Ladies Forbidden. [2] (http://www.snopes.com/language/acronyms/golf.htm)
Gundam - In 2002's Gundam Seed and 2004's Gundam Seed Destiny, "Gundam" was backronymed to General Unilateral Neuro-link Dispersive Autonomic Maneuver (for Earth Alliance mobile suits). This was also expanded as Generation Unsubdued (or Unrestricted) Nuclear (or Network) Drive Assault Module (for ZAFT mobile suits)
Tip - an urban legend claims that "tip" (as in a gratuity for services) is an acronym for To Insure Promptness; this is false.
DeLorean - Don't Ever Lend One Rich Easterner Any Narcotics.
Dodge - Drips Oil, Drops Grease, Everywhere. Dead Or Dying Gutless Engines.
Ford - Ferro Oxide Rust Damage; Found On Rubbish Dump; Found On Road Dead; Fix Or Repair Daily; Fast Only Rolling Downhill; Fucker Only Runs Downhill; F'ed Over Rebuilt Dodge or Fuckin' Old Re-built Dodge and originally it was First On Race Day. An example of a reverse backronym is Driver Returning On Foot. (also fr: «fabrication ordinaire, réparation dispendieuse»)
Holden - Holes, Oil Leaks, Dents and Engine Noises
Honda - Had One, Never Did Again.
Jeep - Just Empty Every Pocket, Junk, Each and Every Part, Just Enough Engine Power (also fr: «j'ai épuisé entièrement patience»)
Air India - Airplanes In Repo In Nicaragua, Delay Inevitable Anyways
Alitalia - Airplane Lands In Tokyo And Luggage In Atlanta; Always Late In Take-off, Always Late In Arrival; A Little Italian Tradition And Lotsa Italian Attitude
Microsoft - My Incompetent Computer Randomly Operates Sensibly/Stupidly On Floating Point Tasks; Most Intelligent Customers Realise Our Software Only Fools Teenagers.
Macintosh - Most Applications (or Machine Always) Crash, If Not, The Operating System Hangs.
Pentium - Produces Erroneous Numbers Through Incorrect Understanding of Math, PC Errors Not Tolerable I'd Use Macintosh
Perl - A high level scripting language common on Unix-like systems, with the common backronym of "Practical Extraction and Report Language", but jokingly referred to as the "Pathologically Eclectic Rubbish Lister". Both expansions appear on the man page. More recently, "Parse Every Random Line", in honor of the extensions proposed for Perl 6. Another less colorful one is "Pathetic Excuse for a Real Language".
Ping - originally a reference to sonar, but now often said to mean "Packet InterNet Grouper".
Spam - originally a reference to the Monty PythonSpam sketch; has been interpreted as Stupid Person's AdvertiseMent; Stupid Puerile Ad Mail; Stuff (or Sewage) Posing As Mail; Send(ing) People Annoying Mail/Messages, Stupid Pointless Annoying Messages, Stupid Posts and Messages.
TWAIN - Technology Without An Interesting [or Ingenious] Name.
WINDOWS - WINDOWS Is Not a Defined Operating/Working System (it is actually a recursive backronym); Will Install Needless Data On Whole System.
Commerce
Acme is the canonical supplier of bizarre, elaborate, and non-functional gadgetry in Warner Brothers' Road Runner cartoons, commonly backronymed to "A (or American) Company Making (or Manufacturing) Everything".
Adidas - Used once as a marketing tagline for the athletic apparel maker -- All Day I Dream About Sports. Also title of a song by Korn: "All Day I Dream About Sex". A popular schoolground one in the UK is "After Dinner I Do A Shit". A well-known Spanish version would be: "Asociación De Idiotas Dispuestos A Superarse" (Association of idiots willing to get better).
Puma - Poor Unprofessional Mimickry of Adidas (de: «Probier Unbedingt Mal Adidas»)
The Arby's chain of restaurants was named after its founders; in the early 1980s the company launched an advertising campaign that used the backronym "America's Roast Beef, Yes Sir!"
CHAPS - Coulda Had A Polo Shirt - Used as a deragatory term towards people who opted for the less expensive CHAPS line over the more expensive Polo Ralph Lauren
Military and police
Army - Aren't Real Men Yet or Aren't Ready for Marines Yet. As a backward backronym, tags on soldier's BDU's (Battle Dress Uniform) can be read "Yes My Retarded Ass Signed Up."
Marine- Muscles Are Required, Intelligence Not Essential; My Ass Rides In Navy Equipment.
Cop - identified by some as "constable on patrol", this originally might not be an acronym at all but a reference to grabbing the alleged villain (sharing origins with "it's a fair cop" or even "to cop a feel") -- Origins murky - could be shortned form of "Copper" since badges were made from the material in certain cities when professional policing began.
Pig - When "pig" came into use as derogatory slang for a policeman, some of its targets retaliated by adopting the phrase "Pride, Integrity, Guts".
A3D was originally a designation of a United States Navystrategic bomber. The bomber had a three_man crew, and lacked ejection seats; it was thus jokingly surmised that the name meant "All Three Dead."
MOAB - Mother Of All Bombs (orginaly Massive Ordinance Air Blast bomb,a US Army weapon)
SOS - devised simply as an easy-to-recognise distress signal, but commonly interpreted as Save Our Ship; Save Our Souls. Also Same Old Shit, Shitting OurSelves and Stuck On Stupid
People
Athletes - Anakin Thought He Loved Everyone, Then Everyone Sneezed
BMW - Bring Money in Wheelbarrows, Big Money Waster; Break My Windows; Basic Marin Wheels, Best Machines in the World, Bob Marley and the Wailers, Black Man's Wheels (in UK Afro-Caribbean culture), Break My Wallet, Be My Wife, Black Man's Willy. A reverse backronym is Wanted Mercedes-Benz;
BMW - the Germans call it "Bayerischer Mistwagen" (Bavarian Manure Wagon), Bayerische Mistwerke (Bavarian Muck Works), "Bring Mir Werkstatt" (Bring Me to Workshop) or "Bei Mercedes Weggeworfen" (Built from Mercedes' Wastebin).
Fiat - Fix It Again Tomorrow; Fix It Again Tony; Found In A Trashbin; Futile Italian Attempt at Transportation; Flat In Every Tyre; Fucking Idiot Asshole Towncar; Failure In Automotive Technology; in German: Fehler In Allen Teilen (all parts are faulty), Für Italiener Ausreichende Technologie (technology sufficient for italians)
BOAC - Better On A Camel; Better On Air Canada; Bit Of A Charlie; Barely Own Any Clocks; Bring Over American Cash; Boeing Only Aircraft Considered (complaint of British aero industry)
BWIA - Better Walk If Able; Britain's Worst Investment Abroad; But Will It Arrive; Bound to Wait In the Airport
Qantas - Queer And Nice Types of Air Steward; Quick And Nasty, Typical Australian Service; Queens (or Queers) And Nymphomanics Trained (or Trading) As Stewards; Quite A Nice Trip, Any Survivors?; Queer And Nuts, Try Another Service. (originally Queensland And Northern Territory Aerial Service)
SABENA - Such A Bad (or Bloody) Experience, Never Again (originally Société Anonyme Belge de l'Exploitation de la Navigation Aerienne)
Sahsa - Stay At Home, Stay Alive (orginally Servicio Aereo de Honduras S.A.)
TACA - Take A Chance Airlines. A backronym in Spanish is Tres Accidentes Cada Año (Three Accidents Each year). TACA was (intentionally) an acronym for Transportes Aéreos Centroamericanos, or Central American Air Transport, after its expansion outside Central America it now stands for Transportes Aéreos del Continente Americano or American Continent Air Transport.
TWA - Try Walking Across; Teeny Weeny Airlines; The Worst Airline; Third World Airlines; Thousands Wandering Aimlessly; Terrorists Welcome Aboard
UTA - Unlikely To Arrive (originally Union des Transports Aeriens)
Computing
AOL - America Off Line, Assholes On Line, American OverLords
APL - A Perfect Language, A Preposterous Language, Another Programming Language, and others.
EMACS - Escape, Meta, Alt, Control, Shift; EMACS Makes A Computer Slow; or Eight Megabytes And Constantly Swapping. In German: EMACS Macht Alle Computer Schön (EMACS makes all computers beautiful).
IBM - Inferior But Marketable; It's Better Manually; Idiots Become Managers; Insidious Black Magic; It's Been Malfunctioning; Incontinent Bowel Movement; I Blame Microsoft (see OS/2); I Buy Macintosh; I've Been Moved (by 1950s and 1960s employees in reference to frequent relocations)
LISP - Lots of Irritating Superfluous Parentheses (alternatively Silly/Stupid Parentheses); Lost In a Sea of Parentheses; Lots of Idiotic, Silly Parentheses after its syntax involving a lot of parentheses indeed.
NT Not Tested. Not There? Nice Try? Nasty and Troublesome? Not to be Trusted? No Thanks? In Spanish, "No Trabaja" for "It Doesn't work". In Finnish, it reads like "en tee", meaning "I won't do (it)".
MCSE - Must Consult Somebody Experienced, Minesweeper Consultant and Solitaire Expert
UNLV - Unfortunately No Longer Virgins (the official meaning of hiphop groupUNLV's name). In the city of Vancouver, WA, this has become "University of Never Leaving Vancouver," likewise with the University of Nevada, Las Vegas.
UMBC - Sometimes refer to as: Under Major Building Construction or UMust Be Crazy.
CMSU - Call Me Stupid University, or the School for Dyslexic Marines.
NEPA - The Nigerian National Electric Power Authority, which because of its variable quality of service is commonly called Never Expect Power Anywhere or No Electric Power Anticipated. When the company became a public limited company and changed its formal name to NEPA PLC, the backronym was changed to No Electric Power Available, Please Light Candle.
NFG - (if the customer asks) New, Fully Guaranteed; otherwise, No F--king Good
Military and police
BATF - Burn All The Families; Burn All Toddlers First (in reference to the Waco disaster)
CID - Coppers In Disguise; more colourfully, Cunts In Disguise
FBI - Full-Blooded Indian; Fry Bread Inspector; From Big Island; Federal Breast Inspector (many are popular T-shirt slogans); also Federal Bureau of Incineration; Fire and Brimstone, Inc., (in reference to the Waco disaster); Female Body Inspector
HRT - Hostage Roasting Team (in reference to the Waco disaster)
NSA - "No Such Agency"; conversely, "Not Secret Anymore".
OPP (police) - Official Party Poopers (also, the OPP backronymed their own name as "Our Purpose Prevention")
PSAC (union) - People Standing Around Complaining (fr: AFPC = «Association des Fortement Paresseux du Canada»)
RESPECT The Unity Coalition, a left wing political party in the UK where RESPECT was later explained officially as Respect, Equality, Socialism, Peace, Environmentalism, Community and Trade Unionism, or among its opponents as Recently Expelled Scottish Politician Endorses Communist Tyranny [3] (http://www.respectcoalition.co.uk/).
NPWS - No People and Weird Stuff_ups (from their habit of making some National parks very difficult to access); No People Welcome, Sorry (originally National Parks and Wildlife Service (Australia))
FCC - During the heyday of citizen's band radio, those who operated illegally or on the edge of the law called the Federal Communications Commission the Friendly Candy Company or Fat Chance Charlie.
DVB - Deficient Video Bandwidth, Definitely Very Boring, Delivering Virtually Bull****
DVD - Defective Video Display, Delivers Virtual Dreck - in computing and audio, "Digital Versatile Disc" is a valid backronym for what was originally a digital video disc; the DVD Consortium supposedly has never claimed that the letters DVD stood for anything specific.
VHS - Virtually Hopeless Signal (originally stood for Vertical Helical Scan but believed by most people to mean Video Home System)
NTSC - Never The Same Color; Never Twice the Same Color; Never Tested Since Christ.
PAL - Peace/Perfect At Last; Picture Always Lousy; Pale And Lurid.
SECAM - System Essentially Contrary to the American Method; Shows Every Colour All Murky.
VOCM - The Dominion of Newfoundland radio callsign prefix VO has typically been backronymed as "voice of", so VOCM would be the "Voice Of Church (of) Mary", voix of common man or (if one were being critical) "Voice Of Complete Morons"
WABC - We'll Always Be Crying, We'll Always Be Cynical
A backronym or bacronym is a type of acronym that begins as an ordinary word, and is later interpreted as an acronym.
When a backronym is peddled as the origin of a word, it is often an example of false etymology; when widely believed, it may have the status of a folk etymology; but more usually it is intended and understood as a joke.
Many 'backronyms' are apronyms, as the word used as the 'backronym' is relevant to the expanded phrase it stands for.