foul - noun

an act that violates the rules of a sport

foul - verb

• hit a foul ball
• make impure
• become or cause to become obstructed
• commit a foul; break the rules
• spot, stain, or pollute
• make unclean
• become soiled and dirty

foul - adjective

• (of a baseball) not hit between the foul lines
• highly offensive; arousing aversion or disgust
• offensively malodorous
• violating accepted standards or rules
• (of a manuscript) defaced with changes
• characterized by obscenity
• disgustingly dirty; filled or smeared with offensive matter
• especially of a ship's lines etc

foul - thesaurus

afoul   befoul   cheating   choke   clog   congest   contaminate   cruddy   defile   dirty   disgustful   disgusting   distasteful   fetid   filthy   foetid   fouled   funky   loathly   loathsome   maculate   nasty   noisome   pollute   repellant   repellent   repelling   revolting   skanky   smelly   smutty   stinking   unsporting   unsportsmanlike   wicked   yucky