erode
erode \i-'ro-d\ vb [L erodere to eat away, fr. e- + rodere to gnaw - more at (MRAT 1: to diminish or destroy by degrees : 1a: to eat into or away by slow destruction of substance : CORRODE 1b: to wear away by the action of water, wind, or glacial ice 1c: to cause to deteriorate or disappear as if by eating or wearing away 2: to produce or form by eroding : to undergo erosion