formation

noun

for·​ma·​tion fȯr-ˈmā-shən 

1

: an act of giving form or shape to something or of taking form : development

the formation of the planets

2

: something that is formed

new word formations

a rock formation

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 of formation

• 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

The Army has a need for any soldier, in any formation, to intuitively control any system. — New Atlas, 15 Oct. 2026

The formation of modern secular states in Egypt, Iran, and Turkey in the early twentieth century was preceded, in the late nineteenth century, by a rise in the popularity of liberalism, constitutionalism, nationalism, and secularism. — Mansoor Moaddel, Foreign Affairs, 15 Oct. 2026

Lupin was created by George Kay in collaboration with François Uzan; Marie Roussin, Florent Meyer and Tigran Rosine also participated in the formation of the series inspired by Maurice Leblanc’s Arsène Lupin character. — Georg Szalai, HollywoodReporter, 15 Oct. 2026

Mourinho has also switched between 4-3-3 and 4-2-3-1 formations lately, and here's the XI that could face Roma tonight. — Jibin Joseph, PC Magazine, 14 Oct. 2026

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
• aeration
• bination
• carnation
• cassation
• castration
• causation
• centration
• cessation
• cetacean
• chelation
• citation

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