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]