acronym

noun

ac·​ro·​nym ˈa-krə-ˌnim 

: 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

ˌa-krə-ˈni-mik 

adjective

acronymically

ˌa-krə-ˈni-mi-k(ə-)lē 

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 sometimes 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

Avoid tech jargon, and don’t try to impress with tech-speak acronyms. —Expert Panel®, Forbes.com, 15 Aug. 2025

The United Nations Educational, Scientific and Cultural Organization, better known by its acronym, UNESCO, added a second heritage site in Jamaica this week, at Port Royal. —Zach Wichter, USA Today, 23 July 2025

Read More: The Race to Explain Why More Young Adults Are Getting Cancer Visually, the school lives up to its acronym: AWSOM. —Alice Park, Time, 21 July 2025

Sometimes the labeling also includes acronyms such HSI, which stands for Homeland Security Investigations, or ERO for ICE Enforcement Removal Operations. —Alexandra Mendoza, Mercury News, 14 July 2025

Word History

Etymology

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

First Known Use

1940, in the meaning defined above

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Kids Definition

acronym

noun

ac·​ro·​nym ˈak-rə-ˌnim 

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