erosion

noun

1.
(geology) the mechanical process of wearing or grinding something down (as by particles washing over it), also figuratively
eating away eroding wearing wearing away
Derived from:
erode
2.
condition in which the earth's surface is worn away by the action of water and wind
Derived from:
erode
3.
a gradual decline of something
fretter
4.
erosion by chemical action
corroding corrosion