Covered with, or containing unclean matter; dirty.
A ship's bottom is foul when overgrown with barnacles
(of words or a way of speaking) obscene, vulgar or abusive.
His foul language causes many people to believe he is uneducated.
Detestable, unpleasant, loathsome.
He has a foul set of friends.
Disgusting, repulsive; causing disgust.
There was a foul smell coming from the toilet.
Ugly; homely; poor.
(of the weather) Unpleasant, stormy or rainy.
Some foul weather is brewing.
Dishonest or not conforming to the established rules and customs of a game, conflict, test, etc.
Foul play is not suspected.
Entangled and therefore restricting free movement, not clear.
We've got a foul anchor.
Outside of the base lines; in foul territory.
Jones hit foul ball after foul ball.