Erosion /(?)/

E·ro·sion

Erosion

n.
  1. The act or operation of eroding or eating away.
  2. The state of being eaten away; corrosion; canker.
  3. The wearing away of the earth's surface by any natural process. The chief agent of erosion is running water; minor agents are glaciers, the wind, and waves breaking against the coast.
  4. a gradual reduction or lessening as if by an erosive force; as, erosion of political support due to scandal; erosion of buying power by inflation. [fig.]