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 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
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.
Earlier stories in that newspaper described López Torres as a ruthless trafficker who has killed dozens and was earlier aligned with Colombia’s right-wing paramilitary forces, known as the United Self-Defense Forces of Colombia, or the Spanish acronym AUC. Antonio Maria Delgado, Miami Herald, 7 Nov. 2025 Known by its acronym, FIM, Food is Medicine is a growing medical movement that’s endorsed by major health organizations such as the American Heart Association. Cari Shane, USA Today, 6 Nov. 2025 Puerto Rico Puerto Rico offers residents the Nutrition Assistance Program (or PAN in its Spanish acronym) in place of SNAP. The Npr Network, NPR, 4 Nov. 2025 Chart-topping hip-hop star NBA YoungBoy is heading back to metro Phoenix for a second stop on this year’s MASA Tour, which is, of course, an acronym for the Make America Slime Again Tour. Ed Masley, AZCentral.com, 3 Nov. 2025 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

Browse Nearby Words

Podcast

Cite this Entry

“Acronym.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/acronym. Accessed 10 Nov. 2025.

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

More from Merriam-Webster on acronym

Last Updated: - Updated example sentences
Love words? Need even more definitions?

Subscribe to America's largest dictionary and get thousands more definitions and advanced search—ad free!