1
: an act of giving form or shape to something or of taking form : development
2
: something that is formed
new word formations
3
: the manner in which a thing is formed : structure
the peculiar formation of the heart
4
: a major kind of plant growth (such as forest, grassland, or tundra) characteristic of a broad ecological region
5
a
: any igneous, sedimentary, or metamorphic rock represented as a unit
b
: any sedimentary bed or consecutive series of beds sufficiently homogeneous or distinctive to be a unit
6
: an arrangement of a body or group of persons or things in some prescribed manner or for a particular purpose
flying in formation

Examples of formation in a Sentence

The book explains the formation of the planets. The soldiers were marching in formation. The team ran on the field and lined up in a punt formation.
Recent Examples on the Web
Examples are automatically compiled from online sources to show current usage. Read More Opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback.
Brendan Cook, Wyoming Whiskey’s master blender, draws a parallel between the formation of the park’s natural terraces and the bourbon aging process. Rachel King, Forbes, 22 Dec. 2024 Prophecy follows the formation of the Bene Gesserit, an order of women who become the puppet masters of the great houses of the Empire on Dune. Anthony D'alessandro, Deadline, 19 Dec. 2024 People come to Medicine Rocks to get away from it all and to camp beneath its unique, Swiss cheese-like sandstone pillar rock formations. Evie Carrick, Travel + Leisure, 18 Dec. 2024 The upcoming route marks a transition from rocks that partially filled the crater during its formation, to rocks from deep inside Mars that were thrown upward to form the rim after an impact, said Ken Farley, project scientist for Perseverance at Caltech in Pasadena. Eric Lagatta, USA TODAY, 18 Dec. 2024 See all Example Sentences for formation 

Word History

First Known Use

15th century, in the meaning defined at sense 1

Time Traveler
The first known use of formation was in the 15th century

Dictionary Entries Near formation

Cite this Entry

“Formation.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/formation. Accessed 6 Jan. 2025.

Kids Definition

formation

noun
1
: a forming of something
2
: something formed
3
: the manner in which a thing is formed : structure, shape
4
: a bed of rocks or series of beds recognizable as a unit
5
: an arrangement or grouping of persons, ships, or airplanes

Medical Definition

formation

noun
1
: an act of giving form or shape to something or of taking form : development
2
: the manner in which a thing is formed : structure

More from Merriam-Webster on formation

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