Source : Webster's Revised Unabridged Dictionary (1913)

Rack \Rack\, v. i.
   To fly, as vapor or broken clouds.

Rack \Rack\, v. i. [imp. & p. p. {Racked}; p. pr. & vb. n.
   {Racking}.] [See {Rack} that which stretches, or {Rock}, v.]
   To amble fast, causing a rocking or swaying motion of the
   body; to pace; -- said of a horse. --Fuller.

Rack \Rack\, v. t. [Cf. OF. vin raqu['e] squeezed from the dregs
   of the grapes.]
   To draw off from the lees or sediment, as wine.

         It is in common practice to draw wine or beer from the
         lees (which we call racking), whereby it will clarify
         much the sooner.                         --Bacon.

   {Rack vintage}, wine cleansed and drawn from the lees.
      --Cowell.

Rack \Rack\, n.
   A fast amble.

Rack \Rack\, n.
   Same as Arrack.

Rack \Rack\, n. [Probably fr. D. rek, rekbank, a rack, rekken to
   stretch; akin to G. reck, reckbank, a rack, recken to
   stretch, Dan. r[ae]kke, Sw. r["a]cka, Icel. rekja to spread
   out, Goth. refrakjan to stretch out; cf. L. porrigere, Gr. ?.
   ? Cf. {Right}, a., {Ratch}.]
   1. An instrument or frame used for stretching, extending,
      retaining, or displaying, something. Specifically:
      (a) An engine of torture, consisting of a large frame,
          upon which the body was gradually stretched until,
          sometimes, the joints were dislocated; -- formerly
          used judicially for extorting confessions from
          criminals or suspected persons.

                During the troubles of the fifteenth century, a
                rack was introduced into the Tower, and was
                occasionally used under the plea of political
                necessity.                        --Macaulay.
      (b) An instrument for bending a bow.
      (c) A grate on which bacon is laid.
      (d) A frame or device of various construction for holding,
          and preventing the waste of, hay, grain, etc.,
          supplied to beasts.
      (e) A frame on which articles are deposited for keeping or
          arranged for display; as, a clothes rack; a bottle
          rack, etc.
      (f) (Naut.) A piece or frame of wood, having several
          sheaves, through which the running rigging passes; --
          called also {rack block}. Also, a frame to hold shot.
      (g) (Mining) A frame or table on which ores are separated
          or washed.
      (h) A frame fitted to a wagon for carrying hay, straw, or
          grain on the stalk, or other bulky loads.
      (i) A distaff.

   2. (Mech.) A bar with teeth on its face, or edge, to work
      with those of a wheel, pinion, or worm, which is to drive
      it or be driven by it.

   3. That which is extorted; exaction. [Obs.] --Sir E. Sandys.

   {Mangle rack}. (Mach.) See under {Mangle}. n.

   {Rack block}. (Naut.) See def. 1
      (f), above.

   {Rack lashing}, a lashing or binding where the rope is
      tightened, and held tight by the use of a small stick of
      wood twisted around.

   {Rack rail} (Railroads), a toothed rack, laid as a rail, to
      afford a hold for teeth on the driving wheel of locomotive
      for climbing steep gradients, as in ascending a mountain.
      

   {Rack saw}, a saw having wide teeth.

   {Rack stick}, the stick used in a rack lashing.

   {To be on the rack}, to suffer torture, physical or mental.
      

   {To live at rack and manger}, to live on the best at
      another's expense. [Colloq.]

   {To put to the rack}, to subject to torture; to torment.

            A fit of the stone puts a kingto the rack, and makes
            him as miserable as it does the meanest subject.
                                                  --Sir W.
                                                  Temple.

Rack \Rack\, n. [AS. hracca neck, hinder part of the head; cf.
   AS. hraca throat, G. rachen throat, E. retch.]
   The neck and spine of a fore quarter of veal or mutton.

Rack \Rack\, n. [See {Wreck}.]
   A wreck; destruction. [Obs., except in a few phrases.]

   {Rack and ruin}, destruction; utter ruin. [Colloq.]

   {To go to rack}, to perish; to be destroyed. [Colloq.] ``All
      goes to rack.'' --Pepys.

Rack \Rack\, n. [Prob. fr. Icel. rek drift, motion, and akin to
   reka to drive, and E. wrack, wreck. ?.]
   Thin, flying, broken clouds, or any portion of floating vapor
   in the sky. --Shak.

         The winds in the upper region, which move the clouds
         above, which we call the rack, . . . pass without
         noise.                                   --Bacon.

         And the night rack came rolling up.      --C. Kingsley.

Rack \Rack\, v. t.
   1. To extend by the application of force; to stretch or
      strain; specifically, to stretch on the rack or wheel; to
      torture by an engine which strains the limbs and pulls the
      joints.

            He was racked and miserably tormented. --Pope.

   2. To torment; to torture; to affect with extreme pain or
      anguish.

            Vaunting aloud but racked with deep despair.
                                                  --Milton.

   3. To stretch or strain, in a figurative sense; hence, to
      harass, or oppress by extortion.

            The landlords there shamefully rack their tenants.
                                                  --Spenser.

            They [landlords] rack a Scripture simile beyond the
            true intent thereof.                  --Fuller.

            Try what my credit can in Venice do; That shall be
            racked even to the uttermost.         --Shak.

   4. (Mining) To wash on a rack, as metals or ore.

   5. (Naut.) To bind together, as two ropes, with cross turns
      of yarn, marline, etc.

   {To rack one's brains} or {wits}, to exert them to the utmost
      for the purpose of accomplishing something.

   Syn: To torture; torment; rend; tear.

Source : WordNet®

rack
     n 1: framework for holding objects
     2: rib section of a forequarter of veal or pork or especially
        lamb or mutton
     3: the destruction or collapse of something; "wrack and ruin"
        [syn: {wrack}]
     4: an instrument of torture that stretches or disjoints or
        mutilates victims [syn: {wheel}]
     5: a support for displaying various articles; "the newspapers
        were arranged on a rack" [syn: {stand}]
     6: a rapid gait of a horse in which each foot strikes the
        ground separately [syn: {single-foot}]

rack
     v 1: go at a rack; "the horses single-footed" [syn: {single-foot}]
     2: stretch to the limits; "rack one's brains"
     3: put on a rack and pinion; "rack a camera"
     4: obtain by coercion or intimidation; "They extorted money
        from the executive by threatening to reveal his past to
        the company boss"; "They squeezed money from the owner of
        the business by threatening him" [syn: {extort}, {squeeze},
         {gouge}, {wring}]
     5: run before a gale [syn: {scud}]
     6: fly in high wind
     7: draw off from the lees; "rack wine"
     8: torment emotionally or mentally [syn: {torment}, {torture},
        {excruciate}]
     9: work on a rack; "rack leather"
     10: seize together, as of parallel ropes of a tackle in order to
         prevent running through the block
     11: torture on the rack