Definition of initialism
: an abbreviation formed from initial letters
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.
First Known Use of initialism
Learn More about initialism
Britannica.com: Encyclopedia article about initialism
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