Abbreviations, Acronyms, and Initialisms

What the heck is an initialism? It's a type of abbreviation, but it's different from an acronym. 

Mignon Fogarty
Episode #165

abbreviationsToday's topic is the difference between abbreviations, acronyms, and initialisms.

Unfortunately, you can't call any abbreviation made up of a phrase's first letters an acronym. Sometimes they are initialisms.


But let's back up. Any shortened form of a word is an abbreviation, for example, "etc." for "etcetera" and "Oct." for "October;" but acronyms are special kinds of abbreviations that can be pronounced as words, such as "NASA" (National Aeronautics and Space Administration) and "OPEC" (Organization of the Petroleum Exporting Countries). This makes acronyms a subset of abbreviations. All acronyms are abbreviations, but not all abbreviations are acronyms.


Initialisms are another type of abbreviation. They're often confused with acronyms because they are made up of letters, so they look similar, but they can't be pronounced as words. "FBI" and "CIA" are examples of initialisms because they're made up of the first letters of "Federal Bureau of Investigation" and "Central Intelligence Agency," respectively, but they aren't usually pronounced as words. Insiders sometimes call the FBI "fibby" and the CIA "see-uh," but most of the world says "F-B-I" and "C-I-A," so they are initialisms.


So remember:

  • Initialisms are made from the first letter (or letters) of a string of words, but can't be pronounced as words themselves. Examples include “FBI,” “CIA,” “FYI” (for your information), and “PR” (public relations).

  • Acronyms are made from the first letter (or letters) of a string of words but are pronounced as if they were words themselves. Examples include “NASA” and “NIMBY”(not in my backyard).

  • Abbreviations are any shortened form of a word.

Sometimes acronyms like "scuba" become so common that they're accepted as words in their own right. "Scuba" was originally an acronym for "self-contained underwater breathing apparatus," but now dictionaries include it as a word.


About the Author

Mignon Fogarty

Mignon Fogarty is the founder of the Quick and Dirty Tips network and creator of Grammar Girl, which has been named one of Writer's Digest's 101 best websites for writers multiple times. The Grammar Girl podcast has also won Best Education Podcast multiple times in the Podcast Awards, and Mignon is an inductee in the Podcasting Hall of Fame. Mignon is the author of the New York Times best-seller "Grammar Girl's Quick and Dirty Tips for Better Writing" and six other books on writing. She has appeared as a guest on the "Oprah Winfrey Show" and the "Today Show" and has been featured in the New York Times, Business Week, the Washington Post, USA Today, CNN.com, and more. She was previously the chair of media entrepreneurship in the Reynolds School of Journalism in Reno, NV. She hates the phrase "grammar nazi" and loves the word "kerfuffle." She has a B.A. in English from the University of Washington in Seattle and an M.S. in biology from Stanford University. Mignon believes that learning is fun, and the vast rules of grammar are wonderful fodder for lifelong study. 

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