ini·​tial·​ism i-ˈni-shə-ˌli-zəm How to pronounce initialism (audio)
: an abbreviation formed from initial letters

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What is the difference between the words acronym and initialism?

Acronym is a fairly recent word, dating from the 1940s, although acronyms existed long before we gave them that name. The term was preceded in English by the word initialism, meaning an abbreviation formed from the initial letters of a phrase, and which has been in use since the late 19th century.

Some people feel strongly that acronym should only be used for terms like NATO, which is pronounced as a single word, and that initialism should be used if the individual letters are all pronounced distinctly, as with FBI. Our research shows that acronym is commonly used to refer to both types of abbreviations.

Examples of initialism in a Sentence

Recent Examples on the Web There are many ways a clue can indicate an abbreviation, initialism or acronym. Sam Corbin, New York Times, 28 May 2023 The additions to the initialism LGBTQ are I (which stands for intersex folks) and A (asexual). Megan Lasher, Seventeen, 6 Apr. 2023 And yet there is something about the homogeneity of these definitions, their recourse to coddling cliché, that makes critical race theory seem like just another version of a fluffier and more familiar three-word initialism, D.E.I.—diversity, equity, and inclusion. Lauren Michele Jackson, The New Yorker, 27 July 2021 Over the past few years, he’s palled around with Bill Clinton, graced the cover of Fortune magazine, and turned himself into a three-letter initialism: SBF. Will Gottsegen, The Atlantic, 11 Nov. 2022 The outbreak — which researchers call by its initialism, HPAI — is relatively novel to this part of this world. Susanne Ruststaff Writer, Los Angeles Times, 3 Oct. 2022 Then, just when one initialism had nothing to do with the other, SPAC vehicles became an ESG thesis. Clifford Pearce, Forbes, 17 Aug. 2022 The British punk rock poet debuts at No. 1 on the Official U.K. Albums Chart with FTHC (an initialism for Frank Turner Hardcore), his ninth studio effort. Lars Brandle, Billboard, 21 Feb. 2022 Athletes from Russia, a country officially banned from the Olympics, competed under the banner of R.O.C., the initialism for the Russian Olympic Committee. New York Times, 9 Aug. 2021 See More

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'initialism.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

Word History

First Known Use

1844, in the meaning defined above

Time Traveler
The first known use of initialism was in 1844

Dictionary Entries Near initialism

Cite this Entry

“Initialism.” Dictionary, Merriam-Webster, Accessed 21 Sep. 2023.

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