The simple definition of an initialism is an abbreviation of multiple words wherein the first letter is taken from each word, and the resulting abbreviation is not pronounced as a word. That last factor is what distinguishes initialisms from acronyms: acronyms are pronounced as words. Initialisms aren't.
Initialisms vs. Acronyms vs. Abbreviations
The fundamental definition of initialism is an abbreviation in which each letter is sounded out individually. By contrast, acronyms are pronounced as words.
To understand the difference, consider NSA (National Security Administration) versus NASA (National Aeronautical and Space Administration). NSA is an initialism; each letter is stated separately (i.e., "N-S-A"). NASA is an acronym (i.e., "nah-sah").
Examples of Initialisms
Initialisms are a common component of both official and conversational English. Initialisms feature in politics, corporate branding, scientific and medical terminology, and casual conversation alike. Here follow many initialism examples, sorted by common categories.
Businesses frequently use initialisms as part of their branding, usually as a way of improving out-of-date, extra long, or not-quite-global phrasing.
- AT&T: American Telephone and Telegraph demonstrates the modernizing effect of using an initialism. Telegraphs aren't in common use anymore, but AT&T keeps its legacy as the very first telecom company (founded by Alexander Graham Bell!) while modernizing its branding with an initialism.
- BMW: Bayerische Motoren Werke (translation: Bavarian Motor Works) is a classic example of using initialism to globalize a brand.
- KFC: Founded by Colonel Harland Sanders in Corbin, Kentucky, KFC (Kentucky Fried Chicken) has become a global brand. Its initialism can be found on stores from Alaska to Singapore.
- IBM: The original tech giant's full name is International Business Machines, but virtually all of their branding relies on this initialism.
- ALS: Amyotrophic lateral sclerosis is just one of many diseases more widely referred to by its initialism. The unwieldy full name is necessary for doctors to specify the particular nature of the illness, but an abbreviation serves for quicker communication.
- EMT: Emergency medical technicians are often the first responders in medical emergencies. It only makes sense for them to shorten their professional name using an initialism.
- ENT: Not to be confused with EMT above, an Ear, Nose and Throat specialist treats illness and injury in those parts of the body.
- PTSD: Initialisms are particularly common when referring to mental illnesses like post-traumatic stress disorder. It simplifies phrasing while keeping things specific.
Initialisms in American politics are so common that they've coined their own joke: "alphabet soup." The use of initialisms in politics around the world reflects a shared need to save time and space without losing specificity.
- ADF: The Australian Defence Force is the umbrella organization containing all branches of the Australian military. Initialisms are common in the military of many countries, aiding clear, concise communication.
- FBI: The Federal Bureau of Investigation, America's police force investigating violations of federal law, is universally known simply as the FBI.
- MP: A common initialism throughout the United Kingdom and Commonwealth countries, MP is shorthand for Member of Parliament. Ironically, the head of a government made up of MPs is usually the PM, or Prime Minister.
- NHS: The United Kingdom has plenty of alphabet soup of its own. The NHS, or National Health Service, is the universal health coverage enjoyed by British natives.
- RCMP: The Royal Canadian Mounted Police, or "Mounties," is Canada's federal police force, also providing law enforcement on the provincial and local level in various parts of the country.
Combining Initialisms and Acronyms
It is the nature of active, living languages that as soon as a rule is set down, exceptions arise. Initialisms are no different. English speakers split the difference between initialisms and acronyms simply by pronouncing certain abbreviations per their individual letters, and other times as single words.
- FAQ: As gamers and other digital natives know well, FAQ stands for "Frequently Asked Questions," a type of online guide that answers questions commonly asked by users of a given digital resource. We have one of our own! As to whether it is pronounced letter by letter (i.e., "F-A-Q") or as the single word "fack," both are considered acceptable.
- JPG: Here's another one for digital natives. Whether this common image extension is sounded out by letter (i.e., "J-P-G") or pronounced as "jay-peg" is, just like FAQ, very much a matter of opinion.
- LSAT: It would be tempting to assume that the LSAT, the admission test for American law school, comes from the same abbreviation as SAT. It doesn't. It simply stands for Law School Admission Test. However, it can be pronounced letter by letter or as "elle-sat."
- MCAT: Another initialism/acronym from the world of standardized testing, the Medical College Admission Test is taken by students who hope to become doctors. Both "M-C-A-T" and "em-cat" are valid pronunciations.
- UCLA: The difference between acronyms and initialisms can also be a deliberate choice on the part of the speaker. In the world of college sports, for instance, it's commonplace for a team's fans (or detractors) to joke about an institution known by an initialism by pronouncing its name as a word - for instance "uhk-lah" instead of "you-see-ell-a" for the University of California, Los Angeles.
Letters in a Line
The distinction between acronyms and initialisms - acronyms are pronounced as a single word, initialisms are pronounced as a series of individual letters - is, like many English rules, very simple and slightly subjective. For some more entertaining abbreviations, check out our list of funny acronyms. Happy learning!