Questions about example sentences with, and the definition and usage of "Fouls"

A: The basic definition of foul is dirty or rotten. You can also describe a bad smell as foul.
Example. "You don't want to foul your drinking water or you'll get sick."

Foul is also used to mean breaking a rule, typically in sports.
In baseball for example. A batter hits the ball, but not inside the playing area or the pitcher throws the ball outside the strike zone of the batter. Both are called foul balls.

Foul sounds exactly the same as fowl. Fowl means birds that are kept for their eggs. Chickens and ducks are fowl.