slough

(noun) necrotic tissue; a mortified or gangrenous part or mass. Synonyms: gangrene, sphacelus.

(noun) a hollow filled with mud.

(noun) a stagnant swamp (especially as part of a bayou).

(noun) any outer covering that can be shed or cast off (such as the cast-off skin of a snake).

(verb) cast off hair, skin, horn, or feathers. Synonyms: shed, molt, exuviate, moult. Example: "Our dog sheds every spring."