soccer (n.) soccer. (n.) 1889, socca, later socker (1891), soccer (1895), originally university slang (with jocular formation -er (3)), from a shortened form of Assoc., abbreviation of association in Football Association (as distinguished from Rugby football). An unusual formation, but those who did it perhaps shied away from making a name out ...
https://www.etymonline.com/word/soccer