Every so often I’m taken to task for referring to an unpronounceable string of letters as an acronym instead of an initialism.
I’m sure there must be contexts in which the distinction is important, but I’ve never felt the need to distinguish between acronyms and initialisms in writing for a general audience.
For one thing, the word initialism in its modern sense is even newer than the word acronym.
There is no entry for initialism in either of my pre-digital dictionaries:
Websters New Collegiate Dictionary (1960).
The Compact Edition of the Oxford English Dictionary (1971).
The presumably more up-to-date Word spell checker puts a red line under the word initialism as I type this article.
Note: The word initialism illustrated by OED citations dated 1899 and 1928 was not being used in the modern sense of initials used to identify an entity like the FBI. It refers to the once-popular practice of signing a published work with initials in order to conceal the identity of the author.
Most readers probably know that an acronym is an invented word made up of the initial letters or syllables of other words, like NASA or NATO. Fewer probably know that an initialism is a type of acronym that cannot be pronounced as a word, but must be read letter-by-letter, like FBI or UCLA.
German had the word Akronym as early as 1921, meaning “a new word made up of initials.”
Americans adopted the word with the English spelling acronym in the 1940s. These dated citations from the OED show that from 1940 to the 21st century, what some speakers now prefer to call initialisms have been called acronyms since the word was adopted into English:
1947 The acronym DDT…trips pleasantly on the tongue and is already a household byword.
1975 The puns on the acronym, ‘CIA’, were spawned by recent disclosures about the intelligence agency.
1985 Called by the acronym SCSD (Schools Construction System Development).
2008 The acronym TSS—Tout Sauf Sarkozy (‘Anything But Sarkozy’).
If it is important to you to distinguish between acronyms (NATO, NASA) and initialisms (FBI, TGIF) then by all means, do so. But if you are speaking to or writing for a general audience, it’s not an error to generalize all words and labels created from initials or parts of words under the broad term acronym.
Initialisms and Acronyms