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
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 chances of formation were 80% on the morning of May 30.
—
Dinah Voyles Pulver, USA Today, 30 May 2026
In 1863, representatives of football clubs from the larger London area met to discuss the formation of a football association and a common set of rules.
—Thomas Adam, The Conversation, 29 May 2026
Since its formation in the 1980s in response to an Israeli invasion, Hezbollah has become an integral part of the Lebanese state and wields considerable power in the country.
—Brittney Melton, NPR, 29 May 2026
Obesity raises the risk of gallstones in general, but data from clinical trials have shown that people on GLP-1 treatments have a 37 percent higher relative risk of developing gallbladder disease, which can include the formation of gallstones.
—Bethany Brookshire, Scientific American, 29 May 2026
See All Example Sentences for formation
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.
Dinah Voyles Pulver, USA Today, 30 May 2026
In 1863, representatives of football clubs from the larger London area met to discuss the formation of a football association and a common set of rules.
—Thomas Adam, The Conversation, 29 May 2026
Since its formation in the 1980s in response to an Israeli invasion, Hezbollah has become an integral part of the Lebanese state and wields considerable power in the country.
—Brittney Melton, NPR, 29 May 2026
Obesity raises the risk of gallstones in general, but data from clinical trials have shown that people on GLP-1 treatments have a 37 percent higher relative risk of developing gallbladder disease, which can include the formation of gallstones.
—Bethany Brookshire, Scientific American, 29 May 2026
See All Example Sentences for formation
Cite this Entry
“Formation.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/formation. Accessed 2 Jun. 2026.
Copy CitationKids Definition
formation
noun
for·ma·tion
fȯr-ˈmā-shən
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
Love words? Need even more definitions?
Merriam-Webster unabridged
