WordNet (r) 3.0 (2006):

run down
    v 1: trace; "We are running down a few tips" [syn: run down,
         check out]
    2: move downward; "The water ran down"
    3: injure or kill by running over, as with a vehicle [syn: run
       down, run over]
    4: use up all one's strength and energy and stop working; "At
       the end of the march, I pooped out" [syn: poop out, peter
       out, run down, run out, conk out]
    5: examine hastily; "She scanned the newspaper headlines while
       waiting for the taxi" [syn: scan, skim, rake, glance
       over, run down]
    6: deplete; "exhaust one's savings"; "We quickly played out our
       strength" [syn: run down, exhaust, play out, sap,
       tire]
    7: pursue until captured; "They ran down the fugitive"

Moby Thesaurus II by Grady Ward, 1.0:

256 Moby Thesaurus words for "run down":
   abandoned, ausgespielt, battered, beat-up, beaten up, belittle,
   blow, break down, bring down, bring into discredit, bring low,
   broken-down, burn out, burned-out, cachectic, calm, calm down,
   cease, collapse, collide, crack up, cry down, debase, debilitated,
   decline, decrepit, decry, degrade, depreciate, derelict, derogate,
   derogate from, deserted, desolate, determine, detract from,
   devitalized, die, die down, dilapidated, diminish, dingy, disabled,
   disapprove of, discover, discredit, disgrace, disparage, dispraise,
   done, done up, down-at-heel, drained, droop, drooping, droopy,
   drop, dwindle, ebb, effete, emptied, enervated, enfeebled,
   eviscerated, exhausted, fade, fagged, fail, failing, faint,
   fainting, fall, fall aboard, fall away, fall off, far-gone,
   fatigue, fatigued, feeble, feeling faint, find, find out, flag,
   flagging, follow, follow a clue, follow up, footsore, forsaken,
   frail, frazzled, gasp, get, get tired, give out, go down,
   go downhill, go off, good and tired, grow weary, halt, head into,
   healthless, hit, hit a slump, hit and run, hit rock bottom,
   hit the skids, hold in contempt, hunt down, in poor health,
   in ruins, incapacitated, infirm, inundate, invalid, invent, jade,
   jaded, knock, laid low, languid, languish, languishing, lapse,
   locate, lose strength, lull, make little of, minimize, molder,
   moribund, nose, nose out, overflow, override, overrun, pacify,
   pale, pant, peak, peaked, peaky, peter out, pine, play out,
   played out, poop out, pooped, puff, puff and blow, put down,
   quiesce, quiet, quieten, ram, ramshackle, reach the depths,
   ready to drop, rediscover, reduced, reduced in health,
   reflect discredit upon, ride down, ride over, ride roughshod over,
   ruined, ruinous, run broadside on, run in, run into, run out,
   run over, run ragged, run to earth, sagging, sail into, sapped,
   seedy, shabby, shadow, shotten, sickly, sink, slide, slight, slip,
   slummy, slump, smell out, sniff out, soothe, speak ill of, spent,
   stalk, stop, strike, submit to indignity, subside, succumb, tacky,
   tail, tattered, tire, tired, tired-winged, toilworn, tottery,
   touch bottom, trace, trace down, track, track down, trail, trample,
   trample on, trample underfoot, trample upon, tranquilize,
   tread upon, tumbledown, uncared-for, unhealthy, unrefreshed,
   unrestored, unsound, untended, used up, valetudinarian,
   valetudinary, wane, waste, waste away, wasted, way-weary, wayworn,
   weak, weaken, weakened, weakly, wearied, weariful, weary,
   weary-footed, weary-laden, weary-winged, weary-worn, wheeze, wilt,
   wilting, with low resistance, wither, wither away, worn, worn-down,
   worn-out