Why is the FIFA World Cup called FIFA World Cup?

Answer 1

"Mundo" is spanish for "world."

"Mundial" is spanish for "worldwide."

This is almost certainly derived from latin and therefore most romantic languages will have similar variations.

Answer 2

Because it is run by the Fédération Internationale de Football Association otherwise known as FIFA, who is football's governing body. The first trophy design that FIFA used from 1930 to 1983 had a cup-like shape at the top of the trophy. That trophy was stolen and never recovered in 1983. FIFA commisioned a new design without a cup at the top of it and that design is still used today.