S: (adj) cheating, dirty, foul, unsporting, unsportsmanlike (violating accepted standards or rules) "a dirty fighter"; "used foul means to gain power"; "a nasty unsporting serve"; "fined for unsportsmanlike behavior"
S: (adj) foul ((of a baseball) not hit between the foul lines)
S: (adj) dirty, foul, marked-up ((of a manuscript) defaced with changes) "foul (or dirty) copy"
S: (adj) filthy, foul, nasty (disgustingly dirty; filled or smeared with offensive matter) "as filthy as a pigsty"; "a foul pond"; "a nasty pigsty of a room"
S: (adj) afoul, foul, fouled (especially of a ship's lines etc) "with its sails afoul"; "a foul anchor"