I wasn't planning to run an item today, it being my birthday, but then I learned my favorite bit of etymology in ages:

It turns out that "soccer" was originally an abbreviation for "association football."

My initial gut feeling was that that sounded awfully unlikely (just because the sounds of the words are so different, even though I know that that's no indication), but MW11 confirms it.

I'm guessing that the term "association football" (first appearance 1873, according to MW11) had to do with the Football Association, founded in 1863.