formation

noun

for·​ma·​tion fȯr-ˈmā-shən 

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

Synonyms

• layout
• format

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

Directed by Chris Smith, Devo tracks the formation, rise, creative evolution, and cultural impact of the post-punk/New Wave/geek rock greats. —Jon Blistein, Rolling Stone, 8 July 2025

Utah claims three top parks, including Bryce Canyon (No. 21) and Arches National Parks (No. 24), with their stunning geological formations. —Hannah Walhout, Travel + Leisure, 8 July 2025

Niko Kovac changed the team’s formation, moving away from using wingers, meaning Gittens’ minutes on the pitch tended to occur in unfamiliar roles. —Chris Weatherspoon, New York Times, 7 July 2025

Everything in our solar system shares a common origin, but objects visiting from other systems are extremely rare portals to the formation of other worlds. —Elizabeth Gamillo, Smithsonian Magazine, 7 July 2025

Word History

First Known Use

15th century, in the meaning defined at sense 1

Phrases Containing formation

• back-formation
• break formation
• I formation
• punt formation
• reticular formation
• self-formation
• spread formation
• T formation

Rhymes for formation

• ablation
• bination
• carnation
• cassation
• castration
• causation
• centration
• cessation
• cetacean
• chelation
• citation
• collation

Kids Definition

formation

noun

for·​ma·​tion fȯr-ˈmā-shən 

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

for·​ma·​tion fȯr-ˈmā-shən 

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