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

Parents need to evaluate how their child's name will affect their identity formation and relationship with both parents while also considering potential challenges like name changes. —Josh Hammer, MSNBC Newsweek, 1 Apr. 2025

Tau tangles typically form years after the formation of another protein called amyloid, which creates plaques in the brain and is one of the first hallmarks of Alzheimer’s. —Melissa Rudy, FOXNews.com, 1 Apr. 2025

Sedona, Arizona, topped a study of the world's most mindful travel destinations for its energy vortexes, red rock formations, and strong spiritual community. —Stacey Leasca, Travel + Leisure, 1 Apr. 2025

But what takes the Mývatn Nature Baths from wonderful to the stuff of fantasy is the scenic view: The baths overlook a valley dotted with craters, volcanic rock formations, and, of course, the occasional Icelandic horse. —Maggie Fuller, AFAR Media, 1 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