The Collaborative International Dictionary of English v.0.48:

Quicken \Quick"en\, v. i.
   1. To come to life; to become alive; to become vivified or
      enlivened; hence, to exhibit signs of life; to move, as
      the fetus in the womb.
      [1913 Webster]

            The heart is the first part that quickens, and the
            last that dies.                       -- Ray.
      [1913 Webster]

            And keener lightnings quicken in her eye. --Pope.
      [1913 Webster]

            When the pale and bloodless east began
            To quicken to the sun.                --Tennyson.
      [1913 Webster]

   2. To move with rapidity or activity; to become accelerated;
      as, his pulse quickened.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Quicken \Quick"en\, v. t. [imp. & p. p. quickened; p. pr. &
   vb. n. Quickening.] [AS. cwician. See Quick, a.]
   1. To make alive; to vivify; to revive or resuscitate, as
      from death or an inanimate state; hence, to excite; to,
      stimulate; to incite.
      [1913 Webster]

            The mistress which I serve quickens what's dead.
                                                  --Shak.
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            Like a fruitful garden without an hedge, that
            quickens the appetite to enjoy so tempting a prize.
                                                  -- South.
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   2. To make lively, active, or sprightly; to impart additional
      energy to; to stimulate; to make quick or rapid; to
      hasten; to accelerate; as, to quicken one's steps or
      thoughts; to quicken one's departure or speed.
      [1913 Webster]

   3. (Shipbuilding) To shorten the radius of (a curve); to make
      (a curve) sharper; as, to quicken the sheer, that is, to
      make its curve more pronounced.
      [1913 Webster]

   Syn: To revive; resuscitate; animate; reinvigorate; vivify;
        refresh; stimulate; sharpen; incite; hasten; accelerate;
        expedite; dispatch; speed.
        [1913 Webster]

WordNet (r) 3.0 (2006):

quicken
    v 1: move faster; "The car accelerated" [syn: accelerate,
         speed up, speed, quicken] [ant: decelerate,
         retard, slow, slow down, slow up]
    2: make keen or more acute; "whet my appetite" [syn: whet,
       quicken]
    3: give life or energy to; "The cold water invigorated him"
       [syn: quicken, invigorate]
    4: show signs of life; "the fetus quickened"
    5: give new life or energy to; "A hot soup will revive me";
       "This will renovate my spirits"; "This treatment repaired my
       health" [syn: animate, recreate, reanimate, revive,
       renovate, repair, quicken, vivify, revivify]

Moby Thesaurus II by Grady Ward, 1.0:

181 Moby Thesaurus words for "quicken":
   accelerate, activate, actuate, advance, advantage, aid, animate,
   arouse, awake, awaken, be begotten, be born, be incarnated, boost,
   brace, brace up, breathe life into, bring into being,
   bring into existence, bring to life, brisk, brisken, buck up,
   bundle, bustle, call into being, call into existence, cheer,
   chirk up, clear the way, come alive, come into being,
   come into existence, come to, come to life, conceive, conduce to,
   contribute to, crack on, crowd, cultivate, dispatch, drive on,
   dynamize, ease, electrify, encourage, endow with life, energize,
   enliven, excite, exhilarate, expedite, explain, facilitate, favor,
   fillip, fire, fortify, forward, fresh up, freshen, freshen up,
   further, gain ground, galvanize, give birth, give life to, goad,
   grease, grease the ways, grease the wheels, haste, hasten,
   hasten on, hearten, help along, hie on, hurry, hurry along,
   hurry on, hurry up, hustle, hustle up, induce, inflame,
   infuse life into, inspirit, invigorate, jazz up, kindle,
   lend wings to, live again, liven, loose, lubricate, make clear,
   make for, make sensitive, make way for, motivate, move, oil,
   open the throttle, open the way, open up, pave the way, pep up,
   perk up, pick up, pick up speed, pique, precipitate,
   prepare the way, press, promote, provoke, push, push forward,
   push on, push through, put forward, put on, put on steam, race,
   railroad through, reanimate, recreate, refine, refresh, refreshen,
   regale, reinvigorate, remove friction, renew, resurge, resuscitate,
   return to life, rev, revive, revivify, rise again, rouse,
   run interference for, rush, rush along, see the light, sensibilize,
   sensitize, set forward, set up, shake up, sharpen, simplify,
   smooth, smooth the way, snap up, soap the ways, spark, speed,
   speed along, speed up, spur, stampede, step on it, step up,
   stimulate, stir, unbar, unblock, unclog, unjam, urge, vitalize,
   vivify, wake, warm, whet, whip, whip along, zip up