The Collaborative International Dictionary of English v.0.48:

Prostrate \Pros"trate\, v. t. [imp. & p. p. Prostrated; p. pr.
   & vb. n. Prostrating.]
   1. To lay fiat; to throw down; to level; to fell; as, to
      prostrate the body; to prostrate trees or plants.
      --Evelyn.
      [1913 Webster]

   2. to overthrow; to demolish; to destroy; to deprive of
      efficiency; to ruin; as, to prostrate a village; to
      prostrate a government; to prostrate law or justice.
      [1913 Webster]

   3. To throw down, or cause to fall in humility or adoration;
      to cause to bow in humble reverence; used reflexively; as,
      he prostrated himself. --Milman.
      [1913 Webster]

   4. To cause to sink totally; to deprive of strength; to
      reduce; as, a person prostrated by fever.
      [1913 Webster]

The Collaborative International Dictionary of English v.0.48:

Prostrate \Pros"trate\, a. [L. prostratus, p. p. of prosternere
   to prostrate; pro before, forward + sternere to spread out,
   throw down. See Stratum.]
   1. Lying at length, or with the body extended on the ground
      or other surface; stretched out; as, to sleep prostrate.
      --Elyot.
      [1913 Webster]

            Groveling and prostrate on yon lake of fire.
                                                  --Milton.
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   2. Lying at mercy, as a supplicant. --Dryden.
      [1913 Webster]

   3. Lying in a humble, lowly, or suppliant posture.
      [1913 Webster]

            Prostrate fall
            Before him reverent, and there confess
            Humbly our faults.                    --Milton.
      [1913 Webster]

   4. (Bot.) Trailing on the ground; procumbent.
      [1913 Webster]

WordNet (r) 3.0 (2006):

prostrate
    adj 1: stretched out and lying at full length along the ground;
           "found himself lying flat on the floor" [syn: flat,
           prostrate]
    2: lying face downward [syn: prone, prostrate]
    v 1: get into a prostrate position, as in submission [syn:
         prostrate, bow down]
    2: render helpless or defenseless; "They prostrated the enemy"
    3: throw down flat, as on the ground; "She prostrated herself
       with frustration"

Moby Thesaurus II by Grady Ward, 1.0:

355 Moby Thesaurus words for "prostrate":
   abject, accumbent, adorant, adoring, afflict, aggrieve, all in,
   anguish, backscratching, beat, beat down, beat up, beaten, bedfast,
   bedridden, beggarly, bend, blow down, blow over, bone-weary,
   bootlicking, bow and scrape, bow down, bowl down, bowl over, break,
   break down, bring down, bring low, bring to tears, broken,
   broken-down, brokenhearted, brought down, brought low, bulldog,
   bulldoze, burn down, burn out, bushed, cast down, chop down,
   confined, conquer, conquered, couch, couchant, couche, cowering,
   crawl, crawling, cringe, cringing, crippled, crouched, crouching,
   crush, crushed, cut down, cut up, dash, dash down, dashed, dead,
   dead-and-alive, dead-tired, deadbeat, debased, debilitate, deck,
   decumbent, deferential, deflate, demoralize, demoralized,
   depressed, desolate, desolated, devotional, devout, disabled,
   disarm, disarmed, disqualified, do in, do up, dog-tired, dog-weary,
   done, done in, done up, down, downcast, downthrown, drained,
   draped, draw tears, drop, embitter, enchain, enervate, exhaust,
   exhausted, fag, fag out, fagged out, fallen, fatigue, fatigued,
   fawning, fell, felled, fetch down, flag, flat, flatten, flattened,
   flattering, floor, floored, footlicking, frazzle, gag, gone,
   grieve, ground, grovel, groveling, hamstring, hamstrung, handcuff,
   hangdog, harass, heart-stricken, heart-struck, heartbroken,
   helpless, hew down, hobble, hog-tie, hog-tied, horizontal,
   hospitalized, hot, humble, humbled, imploring, impotent,
   in childbed, in hospital, in the dust, incapacitated, ingratiating,
   inundate, inundated, invalidated, invalided, jade, knee-high,
   kneel, knock down, knock out, knock over, knock up, knocked flat,
   knocked out, kowtow, laid low, laid up, lay level, lay low,
   lay out, level, lie down, lolling, lounging, low, low-built,
   low-hung, low-level, low-leveled, low-lying, low-set, low-statured,
   lowered, lying, lying down, manacle, master, mastered,
   mealymouthed, mow down, muzzle, neap, neurasthenic, obeisant,
   obsequious, on bended knee, oppress, overcome, overfatigue,
   overpower, overpowered, override, overstrain, overtire, overweary,
   overwhelm, overwhelmed, paralyze, paralyzed, parasitic, played out,
   poop, poop out, pooped, pooped out, powerless, prayerful,
   precative, precatory, precipitate, procumbent, prone,
   prostrate before, prostrated, psych out, pull down, put down,
   quell, quelled, rase, raze, ready to drop, recline, reclining,
   recumbent, reduce, reduced, reduced to jelly, reposing, resupine,
   reverent, reverential, ride down, ruin, ruined, runty,
   send headlong, servile, shake, shaken, short, shot to pieces,
   sick abed, silence, smash, smashed, sniveling, solemn, sorrow,
   spent, sponging, sprawled, sprawling, spread, spread-eagle, squat,
   squatty, steamroller, stooped, strangle, stretched out, stricken,
   stumpy, subdue, subdued, subjugate, subjugated, submerged,
   submissive, submit, subservient, sunk, sunken, supinate, supine,
   suppliant, supplicant, supplicatory, suppress, suppressed,
   sycophantic, take down, tear down, throttle, throw, throw down,
   timeserving, tire, tire out, tire to death, tired out,
   tired to death, toadeating, toadying, toadyish, topple, torment,
   trample down, trample underfoot, tread underfoot, trip, truckle,
   truckling, truss up, tucker, tuckered out, tumble, unbrace, undo,
   undone, unelevated, unglued, unman, unmanned, unnerve, unnerved,
   unstring, unstrung, upset, use up, used up, vanquish, vanquished,
   venerational, venerative, washed-up, weaken, wear, wear down,
   wear on, wear out, wearied, weary, weary unto death, whack down,
   whacked, wilt, wind, wiped out, worn out, worn-out, worshipful,
   worshiping