The Collaborative International Dictionary of English v.0.48:

Erode \E*rode"\, v. t. [imp. & p. p. Eroded; p. pr. & vb. n.
   Eroding.] [L. erodere, erosum; e out + rodere to gnaw. See
   Rodent.]
   1. To eat into or away; to corrode; as, canker erodes the
      flesh. "The blood . . . erodes the vessels." --Wiseman.
      [1913 Webster]

            The smaller charge is more apt to . . . erode the
            gun.                                  --Am. Cyc.
      [1913 Webster]

   2. (Geol. & Phys. Geog.)
      (a) To wear away; as, streams and glaciers erode the land.
      (b) To produce by erosion, or wearing away; as, glaciers
          erode U-shaped valleys.
          [Webster 1913 Suppl.]

   3. to reduce or lessen as if by eroding; as, a politician's
      base of support is eroded by evidence of corruption; the
      buying power of the dollar is eroded by inflation. [fig.]
      [PJC]

WordNet (r) 3.0 (2006):

erode
    v 1: become ground down or deteriorate; "Her confidence eroded"
         [syn: erode, gnaw, gnaw at, eat at, wear away]
    2: remove soil or rock; "Rain eroded the terraces" [syn:
       erode, eat away, fret]

Moby Thesaurus II by Grady Ward, 1.0:

183 Moby Thesaurus words for "erode":
   abate, ablate, abrade, abrase, absorb, abstract, assimilate,
   atomize, bark, bate, be consumed, be eaten away, be gone, bite,
   bleed white, break up, burn up, canker, cease, cease to be,
   cease to exist, chafe, come apart, consume, consume away, corrode,
   crack up, crumble, crumble into dust, curtail, decay, decline,
   decompose, decrease, deduct, deliquesce, dematerialize, depart,
   deplete, depreciate, derogate, destroy, deteriorate, detract, die,
   die away, die out, digest, diminish, disappear, disintegrate,
   disjoin, disorganize, disparage, dispel, disperse, dissipate,
   dissolve, dive, do a fade-out, drain, drain of resources,
   dribble away, drop, drop off, dwindle, eat, eat away, eat into,
   eat up, ebb, erase, evanesce, evaporate, exhaust, exit, expend,
   extract, fade, fade away, fade out, fall, fall away, fall off,
   fall to pieces, file, file away, finish, finish off, fission, flee,
   fly, fray, frazzle, fret, gall, gnaw, gnaw away, go, go away,
   gobble, gobble up, grate, graze, grind, grind down, hide, impair,
   impoverish, ingest, languish, leach, leave no trace,
   leave the scene, lessen, let up, melt, melt away, molder,
   nibble away, oxidize, pass, pass away, pass out, perish, plummet,
   plunge, purify, rasp, raze, reduce, refine, remove,
   retire from sight, retrench, rub, rub away, rub off, rub out,
   ruffle, run low, rust, sag, scour, scrape, scrub, scuff, shorten,
   shrink, sink, sink away, skin, spend, split, squander, subduct,
   subside, subtract, suck dry, suffer an eclipse, swallow,
   swallow up, tail off, take away, take from, tatter, thin, thin out,
   use up, vanish, vanish from sight, wane, waste, waste away, wear,
   wear away, wear down, wear off, wear out, wear ragged, weather,
   weed, withdraw