the act or process of forming or the state of being formed: the formation of ice.
the manner in which a thing is formed; disposition of parts; formal structure or arrangement.
  1. a particular disposition of troops, as in columns, squares, etc.
  2. any required assembling of the soldiers of a unit.
  1. a body of rocks classed as a stratigraphic unit for geologic mapping.Compare member(def 8).
  2. the process of depositing rock or mineral of a particular composition or origin.

Origin of formation

1375–1425; late Middle English formacioun < Latin fōrmātiōn- (stem of fōrmātiō), equivalent to fōrmāt(us) (see form, -ate1) + -iōn- -ion
Related formsfor·ma·tion·al, adjectivemis·for·ma·tion, nounnon·for·ma·tion, nounself-for·ma·tion, nounsub·for·ma·tion, nounsu·per·for·ma·tion, noun

Synonyms for formation Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for formation

Contemporary Examples of formation

Historical Examples of formation

  • Alike as to formation, aspect, and climate, the Causses are unique in France.'

    The Roof of France

    Matilda Betham-Edwards

  • The formation of the associations was effected without the slightest delay.


    Theodor Hertzka

  • Too much guidance and restraint hinder the formation of habits of self-help.


    Samuel Smiles

  • The steep rocky shores have precluded the formation of terraces.

  • These expenses will amount to something very heavy in the formation of a company.

British Dictionary definitions for formation



the act of giving or taking form, shape, or existence
something that is formed
the manner in which something is formed or arranged
  1. a formal arrangement of a number of persons or things acting as a unit, such as a troop of soldiers, aircraft in flight, or a football team
  2. (as modifier)formation dancing
  1. the fundamental lithostratigraphic unit
  2. a series of rocks with certain characteristics in common
ecology a community of plants, such as a tropical rainforest, extending over a very large area
Derived Formsformational, adjective
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 formation

late 14c., from Old French formacion (12c.) or directly from Latin formationem (nominative formatio) "a forming, shaping," noun of action or condition from past participle stem of formare "to form" (see form (v.)).

Online Etymology Dictionary, © 2010 Douglas Harper

formation in Medicine




The act or process of forming something or of taking form.
Something formed.
The American Heritage® Stedman's Medical Dictionary Copyright © 2002, 2001, 1995 by Houghton Mifflin Company. Published by Houghton Mifflin Company.

formation in Science



A long, mappable body of rock that is recognizable by its physical characteristics and by its location within the rock record.
The American Heritage® Science Dictionary Copyright © 2011. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.