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).

The word “soccer” originated in England, and was originally used to differentiate association football from its rugby cousin. Just as rugby football was shortened to “rugger”, the game of association football became known as “soccer” thanks to a shortening of the word “association”.

The word association was used to distinguish their specific sport from other popular games of the day such as “rugby football.” The word soccer comes from a slang abbreviation of the word association, which British players of the day adapted as “assoc,” “assoccer” and eventually soccer or soccer football.

The association in association football was also shortened to soccer. This clips off the first and last three syllables of association, leaving – soc -, onto which that chummy – er was added, yielding soccer. The term is first recorded as socker in 1891. Footer is slightly older, found in that fateful year of 1863.