Source : Webster's Revised Unabridged Dictionary (1913)

Slump \Slump\, n.
   A falling or declining, esp. suddenly and markedly; a falling
   off; as, a slump in trade, in prices, etc. [Colloq.]

Slump \Slump\, v. i.
   1. To slide or slip on a declivity, so that the motion is
      perceptible; -- said of masses of earth or rock.

   2. To undergo a slump, or sudden decline or falling off; as,
      the stock slumped ten points. [Colloq.]

Slump \Slump\, v. t. [Cf. {Lump}; also Sw. slumpa to bargain for
   the lump.]
   To lump; to throw into a mess.

         These different groups . . . are exclusively slumped
         together under that sense.               --Sir W.
                                                  Hamilton.

Slump \Slump\, v. i. [imp. & p. p. {Slumped}; p. pr. & vb. n.
   {Slumping}.] [Scot. slump a dull noise produced by something
   falling into a hole, a marsh, a swamp.]
   To fall or sink suddenly through or in, when walking on a
   surface, as on thawing snow or ice, partly frozen ground, a
   bog, etc., not strong enough to bear the person.

         The latter walk on a bottomless quag, into which
         unawares they may slump.                 --Barrow.

Slump \Slump\, n. [Cf. D. slomp a mass, heap, Dan. slump a
   quantity, and E. slump, v.t.]
   The gross amount; the mass; the lump. [Scot.]

Slump \Slump\, n.
   1. A boggy place. [Prov. Eng. & Scot.]

   2. The noise made by anything falling into a hole, or into a
      soft, miry place. [Scot.]

Source : WordNet®

slump
     n 1: a noticeable deterioration in performance or quality; "the
          team went into a slump"; "a gradual slack in output"; "a
          drop-off in attendance"; "a falloff in quality" [syn: {slack},
           {drop-off}, {falloff}, {falling off}]
     2: a long-term economic state characterized by unemployment and
        low prices and low levels of trade and investment [syn: {depression},
         {economic crisis}]
     v 1: assume a drooping posture or carriage [syn: {slouch}]
     2: fall or sink heavily; "He slumped onto the couch"; "My
        spirits sank" [syn: {slide down}, {sink}]
     3: fall heavily or suddenly; decline markedly; "The real estate
        market fell off" [syn: {fall off}, {sink}]
     4: go down in value; "the stock market corrected"; "prices
        slumped" [syn: {decline}, {correct}]