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• Dewey Decimal System
  Dewey Decimal System

  noun

  a frequently used system of library book classification and arrangement with ten main subject classes
• Dewey decimal system
  Dewey decimal system

  A system used in libraries for the classification of books and other publications. It uses the numbers 000 to 999 to cover the general fields of knowledge and subdivides each field by the use of decimals and letters. Named after its inventor, Melvil Dewey.

Dewey Decimal System

British  

/ ˈdjuːɪ /

noun

1. Also called: decimal classification.   DDS.  a frequently used system of library book classification and arrangement with ten main subject classes

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Dewey decimal system Cultural  

1. A system used in libraries for the classification of books and other publications. It uses the numbers 000 to 999 to cover the general fields of knowledge and subdivides each field by the use of decimals and letters. Named after its inventor, Melvil Dewey.

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Etymology

Origin of Dewey Decimal System

C19: named after Melvil Dewey (1851–1931), US educator who invented the system

Example Sentences

If Judy says she can’t make it as a clerk, she’ll stay up all night learning the Dewey Decimal System.

From Salon • Jun. 9, 2025

She criticized the Dewey Decimal System for including “overwhelmingly Christian” works in a 2013 article called “Queering the Catalog: Queer Theory and the Politics of Correction.”

From Washington Times • Aug. 30, 2023

“I don’t use the Dewey Decimal System or anything, but I think people need to easily find books,” Dixon says.

From Washington Post • Sep. 20, 2017

It’s sure better than studying the Dewey Decimal System.

From Seattle Times • Nov. 20, 2016

Visitors also encountered the latest and arguably most important organizational invention of the century, the vertical file, created by Melvil Dewey, inventor of the Dewey Decimal System.

From "The Devil in the White City" by Erik Larson