slough in WordNet English dictionary

1. cast off hair, skin, horn, or feathers
   "our dog sheds every Spring"
   shed  molt  exuviate  moult  slough 
   

1. necrotic tissue; a mortified or gangrenous part or mass
   gangrene  sphacelus  slough 
   
2. any outer covering that can be shed or cast off (such as the cast-off skin of a snake)
   slough 
   
3. a stagnant swamp (especially as part of a bayou)
   slough 
   
4. a hollow filled with mud
   slough