scummy in WordNet English dictionary

1. of the most contemptible kind
   "abject cowardice"; "a low stunt to pull"; "a low-down sneak"; "his miserable treatment of his family"; "You miserable skunk!"; "a scummy rabble"; "a scurvy trick"
   abject  low  low-down  miserable  scummy  scurvy 
   
2. covered with scum
   "the scummy surface of the polluted pond"
   scummy