foul in WordNet English dictionary

1. especially of a ship's lines etc
   "with its sails afoul"; "a foul anchor"
   afoul  foul  fouled 
   
2. violating accepted standards or rules
   "a dirty fighter"; "used foul means to gain power"; "a nasty unsporting serve"; "fined for unsportsmanlike behavior"
   cheating  dirty  foul  unsporting  unsportsmanlike 
   
3. characterized by obscenity
   "had a filthy mouth"; "foul language"; "smutty jokes"
   cruddy  filthy  foul  nasty  smutty 
   
4. (of a manuscript) defaced with changes
   "foul (or dirty) copy"
   dirty  foul  marked-up 
   
5. highly offensive; arousing aversion or disgust
   "a disgusting smell"; "distasteful language"; "a loathsome disease"; "the idea of eating meat is repellent to me"; "revolting food"; "a wicked stench"
   disgusting  disgustful  distasteful  foul  loathly  loathsome  repellent  repellant  repelling  revolting  skanky  wicked  yucky 
   
6. offensively malodorous
   "a foul odor"; "the kitchen smelled really funky"
   fetid  foetid  foul  foul-smelling  funky  noisome  smelly  stinking  ill-scented 
   
7. disgustingly dirty; filled or smeared with offensive matter
   "as filthy as a pigsty"; "a foul pond"; "a nasty pigsty of a room"
   filthy  foul  nasty 
   
8. (of a baseball) not hit between the foul lines
   foul 
   

1. become or cause to become obstructed
   "The leaves clog our drains in the Fall"; "The water pipe is backed up"
   clog  choke off  clog up  back up  congest  choke  foul 
   
2. spot, stain, or pollute
   "The townspeople defiled the river by emptying raw sewage into it"
   foul  befoul  defile  maculate 
   
3. make impure
   "The industrial wastes polluted the lake"
   pollute  foul  contaminate 
   
4. become soiled and dirty
   foul 
   
5. make unclean
   "foul the water"
   foul 
   
6. commit a foul; break the rules
   foul 
   
7. hit a foul ball
   foul 
   

1. an act that violates the rules of a sport
   foul