The Collaborative International Dictionary of English v.0.48:

Slough \Slough\, n. [OE. slugh, slouh; cf. MHG. sl?ch the skin
   of a serpent, G. schlauch a skin, a leather bag or bottle.]
   1. The skin, commonly the cast-off skin, of a serpent or of
      some similar animal.
      [1913 Webster]

   2. (Med.) The dead mass separating from a foul sore; the dead
      part which separates from the living tissue in
      mortification.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Slough \Slough\, v. i. [imp. & p. p. Sloughed; p. pr. & vb. n.
   Sloughing.] (Med.)
   To form a slough; to separate in the form of dead matter from
   the living tissues; -- often used with off, or away; as, a
   sloughing ulcer; the dead tissues slough off slowly.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Slough \Slough\, a.
   Slow. [Obs.] --Chaucer.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Slough \Slough\, n. [OE. slogh, slough, AS. sl[=o]h a hollow
   place; cf. MHG. sl[=u]ch an abyss, gullet, G. schlucken to
   swallow; also Gael. & Ir. sloc a pit, pool. ditch, Ir. slug
   to swallow. Gr. ????? to hiccough, to sob.]
   1. A place of deep mud or mire; a hole full of mire.
      --Chaucer.
      [1913 Webster]

            He's here stuck in a slough.          --Milton.
      [1913 Webster]

   2. [Pronounced sl[=oo].] A wet place; a swale; a side channel
      or inlet from a river.

   Note: [In this sense local or provincial; also spelt sloo,
         and slue.]
         [1913 Webster]

   Slough grass (Bot.), a name in the Mississippi valley for
      grasses of the genus Muhlenbergia; -- called also drop
      seed, and nimble Will.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Slough \Slough\, v. t.
   To cast off; to discard as refuse.
   [1913 Webster]

         New tint the plumage of the birds,
         And slough decay from grazing herds.     --Emerson.
   [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Slough \Slough\, obs.
   imp. of Slee, to slay. Slew. --Chaucer.
   [1913 Webster]

WordNet (r) 3.0 (2006):

slough
    n 1: necrotic tissue; a mortified or gangrenous part or mass
         [syn: gangrene, sphacelus, slough]
    2: a hollow filled with mud
    3: a stagnant swamp (especially as part of a bayou)
    4: any outer covering that can be shed or cast off (such as the
       cast-off skin of a snake)
    v 1: cast off hair, skin, horn, or feathers; "our dog sheds
         every Spring" [syn: shed, molt, exuviate, moult,
         slough]