It seems that we should stop deriding the Americans for calling 'football' 'soccer'...
' The word "soccer" is actually British. It derives from the game's proper name, association football, with the "soc" bit taken from the word "association" .
The reason it came into popular usage was simple: in the 19th century, football and rugby were both commonly known as football, the former dubbed "association football" and the latter "rugby football". But both phrases are a bit of a mouthful, however, so they were popularly shortened to "soccer" and "rugger" to keep things simple.'
More here https://uk.eurosport.yahoo.com/blogs/the-rio-report/mystery-solved-don-t-blame-usa-real-reason-123344142.html and thanks to the wonderful Danny Baker for the link.