Originally Posted by Karsten Langenfeld
The full and official name of the sport you play is Association football. The full and official name of the sport played here is American football. The names themselves separate one sport from the other and anytime either sport is referred to as "football", that's a nickname. It's just that the nickname is shared between the two sports.
Also, the football may not be round but neither is an Association football. It's a truncated icosahedron. That ain't completely round either.
Plus, if you think about it, if sports should be named after what it's in contact with, Association football should be called "grassball".