Dewey decimal classification
nounThe American Heritage® Dictionary of the English Language, 4th edition Copyright © 2010 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.
A system used in libraries for organizing nonfiction publications into subject categories corresponding to three-digit numerals, with further specification expressed by numerals following a decimal point.
Origin: After Melvil Dewey.