WordNet (r) 3.0 (2006):

wear down
    v 1: exhaust or get tired through overuse or great strain or
         stress; "We wore ourselves out on this hike" [syn: tire,
         wear upon, tire out, wear, weary, jade, wear
         out, outwear, wear down, fag out, fag, fatigue]
         [ant: freshen, refresh, refreshen]
    2: deteriorate through use or stress; "The constant friction
       wore out the cloth" [syn: wear, wear off, wear out,
       wear down, wear thin]

Moby Thesaurus II by Grady Ward, 1.0:

91 Moby Thesaurus words for "wear down":
   ablate, abrade, affect, argue into, beat, bend, bias, bring over,
   bring round, bring to reason, burn out, captivate, charm, color,
   con, convince, debilitate, dispose, do in, do up, drain, draw over,
   enervate, erode, exhaust, fag, fag out, fatigue, flag, fray,
   frazzle, fret, gain, gain over, harass, hook, hook in, incline,
   induce, influence, jade, knock out, knock up, lead, move, outtalk,
   overfatigue, overstrain, overtire, overweary, persuade, poop,
   poop out, predispose, prevail on, prevail upon, prevail with,
   prompt, prostrate, rub off, sell, sell one on, soften up, sway,
   talk into, talk over, tatter, tinge, tire, tire out, tire to death,
   tone, tucker, use up, wangle, wangle into, weaken, wear, wear away,
   wear off, wear on, wear out, wear ragged, weary, weather,
   weigh with, wilt, win, win over, wind, work