The Grand Canyon is a monumental example of erosion—the entire canyon was carved by the flow of the Colorado River, which slowly dug the canyon out of stone over the course of eons.

Erosion is the wearing away of sand, soil, or rock by water or wind. But it also has a metaphorical sense. The erosion of standards for behavior in society means that our grandparents would be shocked by what passes for good manners today.

Definitions of erosion
  1. noun
    (geology) the mechanical process of wearing or grinding something down (as by particles washing over it)
    synonyms: eating away, eroding, wearing, wearing away
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    chatter mark
    marks on a glaciated rock caused by the movement of a glacier
    the erosive process that reduces the size of glaciers
    abrasion, attrition, corrasion, detrition
    erosion by friction
    beach erosion
    the erosion of beaches
    (geology) the erosion of soil as a consequence of sand and dust and loose rocks being removed by the wind
    the process of erosion whereby a level surface is produced
    soil erosion
    the washing away of soil by the flow of water
    wash, washout
    the erosive process of washing away soil or gravel by water (as from a roadway)
    type of:
    geologic process, geological process
    (geology) a natural process whereby geological features are modified
  2. noun
    condition in which the earth's surface is worn away by natural processes, including weathering, transportation, dissolution, and abrasion
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    type of:
    environmental condition
    the state of the environment
  3. noun
    a gradual decline of something
    “after the accounting scandal there was an erosion of confidence in the auditors”
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    type of:
    decline, diminution
    change toward something smaller or lower
  4. noun
    erosion by chemical action
    synonyms: corroding, corrosion
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    indentation, pitting, roughness
    the formation of small pits in a surface as a consequence of corrosion
    rust, rusting
    the formation of reddish-brown ferric oxides on iron by low-temperature oxidation in the presence of water
    type of:
    chemical action, chemical change, chemical process
    (chemistry) any process determined by the atomic and molecular composition and structure of the substances involved
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