The word soccer was actually invented in Great Britain, and how it came to be is shocking indeed. Back in the late nineteenth century, when universities and organizations began playing the game seriously, they called it association football. This is self-explanatory; the word football already existed (with a transparent origin), and the preceding term association denoted that they played in official federations. However, among college players, a colloquial version of the word appeared: socca, which was an abbreviated version of as-socia-ted. This became rather popular to say and was soon picked up by Americans playing the game. Because of their linguistic patterns of adding jocular formations, especially around New England, where it was most popular, the word took on an -er ending and thus became soccer. This grew in usage until every American was saying it, while the Brits were still split fifty-fifty between socca and football by itself. By the 1980s, the newly headstrong and Thatcherized English wanted to distinguish themselves from those vulgar Americans, and stopped saying socca altogether. Now everyone thinks we wanted to change from them! Speaking of fake etymologies, at one point the term socker was also attested, which would have caused a bunch of amateur origin-guessing if it had survived the natural selection process. Luckily soccer's spelling was becoming much more standardized, and this didn't occur.
Adam Aleksic, a rising sophomore studying linguistics and government at Harvard University, has been described as the internet's sixth most famous etymologist. He also has disturbing interests in politics, vexillology, geography, board games, conlanging, and law.