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

• arrangement
• configuration
• conformation
• format
• layout
• setout
• setup

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

Guided tours lead visitors along pathways, share the history of the caverns, and highlight its wildlife and unique formations, like the 250-foot-deep bottomless pool. —Tara Massouleh McCay, Southern Living, 13 Apr. 2025

Yapi started in place of winger Kévin Cabral and the Rapids switched up the formation to a fluid-looking 4-4-2. —Braidon Nourse, Denver Post, 12 Apr. 2025

The men were captured on video rolling boulders over a cliff at Lake Mead National Recreation Area, causing more than $1,000 in damage to the rock formation, McClatchy News reported. —Brooke Baitinger, Sacbee.com, 11 Apr. 2025

The Context Video that captured two visitors to the Lake Mead National Recreation Area pushing rock formations off a cliff went viral last year. —Raja Krishnamoorthi, MSNBC Newsweek, 9 Apr. 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