[klas-uh-fi-key-shuh n]


the act of classifying.
the result of classifying or being classified.
one of the groups or classes into which things may be or have been classified.
Biology. the assignment of organisms to groups within a system of categories distinguished by structure, origin, etc. The usual series of categories is phylum (or, especially in botany, division), class, order, family, genus, species, and variety.
the category, as restricted, confidential, secret, or top secret, to which information, a document, etc., is assigned, as by a government or military agency, based on the degree of protection considered necessary to safeguard it from unauthorized use.
Library Science. any of various systems for arranging books and other materials, especially according to subject or format.

Origin of classification

1780–90; < Latin classi(s) class + -fication
Related formsclas·si·fi·ca·to·ry [kluh-sif-i-kuh-tawr-ee, -tohr-ee, klas-uh-fi- or, esp. British, klas-uh-fi-key-tuh-ree] /kləˈsɪf ɪ kəˌtɔr i, -ˌtoʊr i, ˈklæs ə fɪ- or, esp. British, ˌklæs ə fɪˈkeɪ tə ri/, adjectivecla·si·fi·ca·to·ri·ly, adverbclas·si·fi·ca·tion·al, adjectivemis·clas·si·fi·ca·tion, nounnon·clas·si·fi·ca·tion, nouno·ver·clas·si·fi·ca·tion, nounpre·clas·si·fi·ca·tion, noun Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for classification

Contemporary Examples of classification

Historical Examples of classification

  • I know it is said that this means the classification of local preachers.

    Samantha Among the Brethren, Part 7.

    Josiah Allen's Wife (Marietta Holley)

  • Of course, the classification sometimes overlaps, like all classification.

    Alarms and Discursions

    G. K. Chesterton

  • He was quick in his classification, for he knew them at once for man-animal noises.

    White Fang

    Jack London

  • The classification of freights applies to all the lines, regardless of class.

    The Railroad Question

    William Larrabee

  • When these rates and the classification conflict, these rates will govern.

    The Railroad Question

    William Larrabee

British Dictionary definitions for classification



systematic placement in categories
one of the divisions in a system of classifying
  1. the placing of animals and plants in a series of increasingly specialized groups because of similarities in structure, origin, molecular composition, etc, that indicate a common relationship. The major groups are domain or superkingdom, kingdom, phylum (in animals) or division (in plants), class, order, family, genus, and species
  2. the study of the principles and practice of this process; taxonomy
government the designation of an item of information as being secret and not available to people outside a restricted group
Derived Formsclassificational, adjectiveclassificatory, adjective

Word Origin for classification

C18: from French; see class, -ify, -ation
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012

Word Origin and History for classification

1772, "action of classifying," noun of action from Latin stem of classify, or from French classification. Meaning "result of classifying" is from 1789.

Online Etymology Dictionary, © 2010 Douglas Harper

classification in Medicine




A systematic arrangement into classes or groups.
The systematic grouping of organisms into categories on the basis of evolutionary or structural relationships between them; taxonomy.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

classification in Science



The systematic grouping of organisms according to the structural or evolutionary relationships among them. Organisms are normally classified by observed similarities in their body and cell structure or by evolutionary relationships based on the analysis of sequences of their DNA. See more at cladistics Linnean. See Table at taxonomy.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.