: a word (such as NATO, radar, or laser) formed from the initial letter or letters of each of the successive parts or major parts of a compound term
also : an abbreviation (such as FBI) formed from initial letters : initialism

Frequently Asked Questions

What is the difference between an acronym and an initialism?

Both acronyms and initialisms are made up of the first letter or letters of the words in a phrase. The word acronym typically applies when the resulting thing can be read as a word; for example, radar comes from "radio detection and ranging" and scuba comes from "self-contained underwater breathing apparatus." The word initialism only applies when the resulting thing is read as an abbreviation; for example DIY, which comes from "do it yourself," is pronounced by saying the names of the letters. Note that the word acronym is also often used to mean "initialism."

What is the difference between an acronym and an abbreviation?

An acronym is a kind of abbreviation. Abbreviations can be shortened forms of any kind. For example, appt is an abbreviation of appointment, and ASAP is an abbreviation of as soon as possible. ASAP, however, also qualifies as an acronym because it is made up of the initial letters of the phrase it comes from: as soon as possible.

Is OK an acronym?

OK is technically an acronym. It comes from the phrase "oll korrect," a humorous alteration of "all correct."

Examples of acronym in a Sentence

The North Atlantic Treaty Organization is known by the acronym “NATO.”
Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Chile, Cuba, Norway, and Venezuela all played a role in the 2016 talks that concluded the Colombian government’s half-century war with the Revolutionary Armed Forces of Colombia (known by its Spanish acronym, FARC). Matt Waldman, Foreign Affairs, 13 Aug. 2026 The four alleged members of the Jalisco New Generation cartel, known by its Spanish acronym CJNG, were arrested in the Czech Republic in June, Justice Department officials said. CBS News, 12 Aug. 2026 From their social media accounts, authorities identified the two brothers as part of a group of local rappers who commonly use the acronym NBS in their stage names. Nate Gartrell, Mercury News, 11 Aug. 2026 In both shows, romance takes a back seat as a minor subplot, proving that WOCA (an acronym for women of a certain age that Ride Or Die fully embraces) are interested in more than love stories and relationship triangles. Nellie Andreeva, Deadline, 4 Aug. 2026 See All Example Sentences for acronym

Word History

Etymology

probably borrowed from German Akronym, Akronymon, from akr- acr- + -onym, -onymon -onym

First Known Use

1940, in the meaning defined above

Time Traveler
The first known use of acronym was in 1940

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Cite this Entry

“Acronym.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/acronym. Accessed 17 Aug. 2026.

Kids Definition

: a word (as radar) formed from the beginning letter or letters of each or most of the parts of a compound term

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