Here is my definition (It is used by sportaccord)
A sport must
- have an element of competition
- be in no way harmful to any living creature
- not rely on equipment provided by a single supplier
- not rely on any "luck" element specifically designed into the sport.
Just because something has an international federation does not mean it is a sport, nothing about a federation should make it a sport or not, I hope you aren't trying to say that Kickball isn't a sport, because there is no federation for that, therefore, this definition is flawed