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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

For those creeped out by the thought of machines turning evil, recent developments are enough to pine for the days when the Dewey Decimal System reigned supreme.

From Seattle Times • Feb. 26, 2023

I have no idea where this book, translated gracefully from the Dutch by David McKay, will land in the Dewey Decimal System.

From New York Times • Sep. 18, 2022

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