acronym

noun

ac·​ro·​nym ˈa-krə-ˌnim How to pronounce acronym (audio)
: 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
acronymic adjective
acronymically adverb

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.
Something more memorable with fewer acronyms would go a long way. Matthew Buzzi, PC Magazine, 1 June 2026 ImaZins via Getty Images CORTIS — an acronym for Color Outside the Lines — is a five-member boy group under Big Hit Music and Republic Records in the US, consisting of James, Juhoon, Martin, Seonghyeon, and Keonho. Hannah Abraham, Forbes.com, 1 June 2026 The response has not kept pace with one of the fastest-spreading outbreaks on record, Doctors Without Borders, known by the French acronym MSF, warned Saturday. Justin Kabumba, Los Angeles Times, 30 May 2026 Former supporters of Bolivia's long-dominant Movement Toward Socialism party, known by its Spanish acronym MAS, who helped vault Paz to power over more conservative rivals, have increasingly voiced concern that his government doesn't represent them. ABC News, 27 May 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 4 Jun. 2026.

Kids Definition

acronym

noun
ac·​ro·​nym ˈak-rə-ˌnim How to pronounce acronym (audio)
: 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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