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]

Moby Thesaurus II by Grady Ward, 1.0:

166 Moby Thesaurus words for "slough":
   abandon, baygall, bilge, bilgewater, bind, bog, bottom, bottomland,
   bottoms, buffalo wallow, caries, carrion, case, cashier, cast,
   cast aside, cast away, cast off, chuck, chuckhole, clutch,
   complication, crunch, decay, decomposition, deep-six, desquamation,
   discard, dishwater, dispose of, ditch, ditchwater, dry gangrene,
   dry rot, dump, eighty-six, eliminate, embarrassing position,
   embarrassment, everglade, exuviae, exuviate, fen, fenland,
   fine how-do-you-do, foulness, gangrene, garbage, gas gangrene,
   get quit of, get rid of, get shut of, give away, glade,
   hell to pay, hobble, hog wallow, holm, hot water, how-do-you-do,
   husk, imbroglio, jam, jettison, jilt, junk, loblolly, marais,
   marish, marsh, marshland, meadow, mere, mess, mire, mix,
   moist gangrene, molt, moor, moorland, morass, mortification, moss,
   muckhole, mud, mud flat, mud puddle, mudhole, necrosis,
   necrotic tissue, noma, offal, offscourings, parlous straits,
   part with, pass, peat bog, pickle, pinch, plight, pod, predicament,
   pretty pass, pretty pickle, pretty predicament, puddle,
   putrefaction, putrescence, putridity, putridness, quagmire,
   quicksand, rancidity, rancidness, rankness, refuse, reject, remove,
   riffraff, rot, rottenness, salt marsh, scrap, scrape, scum, scurf,
   sewage, sewerage, shed, shell, shuck, skin, slip, slob land, slop,
   slops, sough, sphacelation, sphacelus, spoilage, spot, squeeze,
   stew, sticky wicket, strait, straits, sump, swale, swamp,
   swampland, swill, taiga, throw away, throw off, throw out,
   throw over, throw overboard, tight spot, tight squeeze, tightrope,
   tooth decay, toss overboard, tricky spot, unholy mess, wallow,
   wash