[ fawr-mey-shuhn ]
/ fɔrˈmeɪ ʃən /
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See synonyms for: formation / formational on Thesaurus.com


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.



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Origin of formation

1375–1425; late Middle English formacioun<Latin fōrmātiōn- (stem of fōrmātiō), equivalent to fōrmāt(us) (see form, -ate1) + -iōn--ion
Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2021

British Dictionary definitions for formation

/ (fɔːˈmeɪʃən) /


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
formational, 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

Medical definitions for formation

[ fôr-māshən ]


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.

Scientific definitions for formation

[ fôr-māshən ]

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.
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