ag·​gra·​da·​tion ˌa-grə-ˈdā-shən How to pronounce aggradation (audio)
: a modification of the earth's surface in the direction of uniformity of grade by deposition
aggradational adjective

Example Sentences

Recent Examples on the Web Number one is aggradation of the channel bed, and number two, a mega flood. Mark Schleifstein,, 12 Dec. 2017

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'aggradation.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

Word History


aggrade "to fill with detrital material, build up by aggradation" (from ad- + -grade, as in degrade) + -ation (after degradation)

Note: Aggrade and aggradation were apparently introduced by the geologist Rollin D. Salisbury in Surface Geology: Report of Progress, from the Annual Report of the State Geologist for 1892, Trenton, N.J.: Geological Survey of New Jersey, 1893, p. 103.

First Known Use

1898, in the meaning defined above

Time Traveler
The first known use of aggradation was in 1898

Dictionary Entries Near aggradation

Cite this Entry

“Aggradation.” Dictionary, Merriam-Webster, Accessed 7 Dec. 2022.

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