Does the rest of the English speaking world generally understand what an American means when they say "soccer", or does it help to clarify by adding "football"?
If I'm talking to an English speaker from outside of the US, is there any confusion if I say "soccer"?
For example, when I was in college a friend asked for a "torch". I was confused for quite some time, because I didn't know it was another word for "flashlight". Does the same thing happen with the word "soccer"? Should I clarify by saying, "...or football"?
The word Soccer is actually British - it's short for Association as in Association Football, although it's slang from Oxford University of all places, and is late Victorian.
Irony is a surprising number of "Americanisms" turn out to be old British terms that died out in Britain but reached and continued in the US.