I know that it is very common to hear the meanings of words explained by an anecdote about how they used to be an acronym that meant something related to their current meaning. I also know that this is pretty much always untrue. In our modern world, new words are often created by acronymizing a descriptive phrase, but from what I understand, this wasn't done very much in English prior to WWII.
So, my question is: are there ANY old words in the English language that are actually acronyms??
I assume that the oldest recent examples you're thinking of are scuba, radar, and laser, which were all post-WWII as far as I know. I don't really know of anything older than those, so my post is probably not helpful. Mostly, I just wanted to mention that a friend of mine recently mentioned an acronym I hadn't heard before, but I love it. It's a sarcastic take on "NIMBY" ("Not in My Backyard") he called "BANANA": "Build Absolutely Nothing Anywhere Near Anything." Awesome.
What immediately comes to my mind is the Navy SeaBees, which is kinda' a reverse acronym, since it was originally "CBs" (Construction Battalions) in WW2. But then it became "SeaBees" which seems to be a step backward. But the name stuck.
There was a considerable use of acronyms in the mid 1800s. SGQ was short for "Sound on the Goose Question". I also believe OK (okay) originated around that time.
Emmett
According to Wikipedia, the US Junior Chamber organization was established in 1920. There doesn't seem to be any information on when they started calling themselves "Jaycees".