ac·​ro·​nym | \ˈa-krə-ˌnim \

Definition of acronym 

: 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

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Other Words from acronym

acronymic \ ˌa-​krə-​ˈni-​mik \ adjective
acronymically \ -​mi-​k(ə-​)lē \ adverb

What's the difference between an abbreviation and an acronym?

Some people are unsure of whether to call ASAP or appt abbreviations or acronyms. Both abbreviation and acronym are used to refer to a shortened form, but an acronym is a shortened form of a phrase and is usually made up of the initial letters of that phrase. For example, NATO comes from “North Atlantic Treaty Organization,” and ASAP comes from “as soon as possible.” Abbreviations, on the other hand, can be shortened forms of words or phrases, and need not necessarily be made up of the initial letters of either. ASAP and appt (for appointment) are both considered abbreviations, but only ASAP is an acronym. Acronyms are a type of abbreviation.

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.

Did You Know?

Acronym was created by combining acr- ("beginning") with -onym, ("name" or "word"). You may recognize -onym in other familiar English words such as pseudonym and synonym. English speakers borrowed -onym directly from the Greek (it derives from onyma, the Greek word for "name"). Acr- is also from Greek, but it made a side trip through Middle French on its way to English.

Examples of acronym in a Sentence

The North Atlantic Treaty Organization is known by the acronym “NATO.”

Recent Examples on the Web

The second important feature is the focus on human-machine interaction (HMI — yes, there’s always an acronym). David Roberts, Vox, "Here’s how self-driving cars could catch on," 8 May 2018 Health acronyms of the month: Science sometimes comes up with clever acronyms that help the rest of us understand the latest in innovation. Tom Still, Milwaukee Journal Sentinel, "Still: Wisconsin should plug into electric car trend; government 5G network a bad idea," 2 Feb. 2018 The Main Intelligence Directorate, better known by the acronym GRU from its Russian name, is the Kremlin's military intelligence arm. NBC News, "What is the GRU? Mueller indicted the spy agency's operatives.," 13 July 2018 The acronym stands for Alert, Lockdown, Inform, Counter, Evaluate. Denise Coffey, Courant Community, "Thompson To Roll Out ALICE Training," 26 June 2018 The acronym stands for perseverance, respect, intellectual growth, diligence and empathy. Leah Brennan,, "Dumbarton Middle School holds ceremony celebrating completion of two-year renovation," 6 June 2018 The two men were found dead after an apparent murder-suicide in 2011, making her the only surviving core member of the group, known by the acronym NSU. Fox News, "A look at the 5 defendants in Germany's neo-Nazi trial," 10 July 2018 Hoping to prevent a recurrence, the Pentagon is discussing a plan to continue U.S. airstrikes and special operations raids against Islamic State, also known by the acronym ISIS, in Syria even after U.S. ground forces withdraw. David S. Cloud,, "Trump administration struggles to win Arab support for helping rebuild Syria, leaving U.S. pullout uncertain," 28 Apr. 2018 Both Russia and China abstained during the vote to continue the U.N. Mission for Justice and Support in Haiti — known by the acronym MINUJUSTH — for another year when its mandate expires on Sunday. Jacqueline Charles, miamiherald, "U.N. mission in Haiti extended for another year by Security Council | Miami Herald," 10 Apr. 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'acronym.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of acronym

1940, in the meaning defined above

History and Etymology for acronym

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

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Last Updated

6 Nov 2018

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Time Traveler for acronym

The first known use of acronym was in 1940

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English Language Learners Definition of acronym

: a word formed from the first letters of each one of the words in a phrase


ac·​ro·​nym | \ˈa-krə-ˌnim \

Kids Definition of acronym

: a word formed from the first letter or letters of the words of a compound term The word “radar” is an acronym for “radio detecting and ranging.”

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Comments on acronym

What made you want to look up acronym? Please tell us where you read or heard it (including the quote, if possible).


something that serves to warn or remind

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