expansion

American  

[ik-span-shuhn] / ɪkˈspæn ʃən /

noun

• expansions
  plural

1. the act or process of expanding.

2. the state or quality of being expanded.

3. the amount or degree of expanding.

4. an expanded, dilated, or enlarged portion or form of a thing.

   The present article is an expansion of one he wrote last year.

5. anything spread out; expanse.

6. Mathematics.

   1. the development at length of an expression indicated in a contracted form, as a 2 + 2 ab + b 2 for the expression (a +b ) 2 .

   2. any mathematical series that converges to a function for specified values in the domain of the function, as 1 + x + x 2 + … for 1/(1 −x ) when x < 1.

7. Machinery. that part of the operation of an engine in which the volume of the working medium increases and its pressure decreases.

8. an increase in economic and industrial activity (opposed to contraction).

9. additional content for a video game, card game, board game, etc., that significantly expands or alters the way the game is played.

   I really improved my deck with cards from the latest expansion.

   You can play the stand-alone expansion without ever buying the original game.

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expansion British  

/ ɪkˈspænʃən /

noun

1. the act of expanding or the state of being expanded

2. something expanded; an expanded surface or part

3. the degree, extent, or amount by which something expands

4. an increase, enlargement, or development, esp in the activities of a company

5. maths

   1. the form of an expression or function when it is written as the sum or product of its terms

   2. the act or process of determining this expanded form

6. the part of an engine cycle in which the working fluid does useful work by increasing in volume

7. the increase in the dimensions of a body or substance when subjected to an increase in temperature, internal pressure, etc

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expansion Scientific  

/ ĭk-spăn′shən /

1. An increase in the volume of a substance while its mass remains the same. Expansion is usually due to heating. When substances are heated, the molecular bonds between their particles are weakened, and the particles move faster, causing the substance to expand.

2. A number or other mathematical expression written in an extended form. For example, a ² + 2 ab + b ² is the expansion of (a + b) ².

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Other Word Forms

Derived Forms

• nonexpansion
  noun
• overexpansion
  noun
• preexpansion
  noun
• reexpansion
  noun
• self-expansion
  noun
• superexpansion
  noun
• antiexpansion
  adjective
• expansional
  adjective
• expansionary
  adjective

Inflected Forms

Nouns

• expansions
  plural

Etymology

Origin of expansion

First recorded in 1605–15; from Late Latin expānsiōn-, stem of expānsiō; equivalent to expanse + -ion

Explanation

Expansion is what happens when something becomes bigger or more extensive. If you enjoy good pastry, you will be excited by the expansion of the bakery, but be careful or you will also see the expansion of your waistline. The noun expansion is from the Latin word expansionem, which means a spreading out. Another definition for expansion is an elaboration or expanding upon something. If you're a teacher, you might be asked to give an expansion of the short talk you give students, "Homework Stinks: But Why We Need It Anyway" to parents at the school open house.

Example Sentences

See Examples For:

expansion expansions

The result has been a huge expansion of two popular government bond trades, arbitraging Treasurys or British gilts against bond futures or swaps.

From The Wall Street Journal ● Aug. 16, 2026

It subsequently went into gradual decline under the ownership of the American group General Motors, which long restricted its international expansion to avoid competition with other GM subsidiaries.

From Barron's ● Aug. 16, 2026

"We believe growth is progress – leading to vitality, expansion of life, increasing knowledge, higher well being," he wrote.

From BBC ● Aug. 14, 2026

Mark Walter’s sale of the Lakers, which valued the organization at $12.5 billion, was reportedly motivated by the spiraling price for an NBA expansion team in Las Vegas.

From Los Angeles Times ● Aug. 14, 2026

Before the recent overseas expansion of Europeans speaking Indo-European languages, Austronesian was the most widespread language family in the world.

From "Guns, Germs, and Steel: The Fates of Human Societies" by Jared M. Diamond

Looking forward, Qi said, "We are going to explore more satellite data and look for better understanding of the expansions."

From Science Daily ● Aug. 3, 2026

“These changes and expansions give even more people a place for their music to be respected, heard and evaluated,” the Recording Academy’s Harvey Mason Jr. said.

From Los Angeles Times ● Jul. 29, 2026

This last rule is perhaps the most important; it would prevent the court from providing under-the-radar expansions of the law as it tried to do in the aftermath of Callais.

From Slate ● Jul. 29, 2026

For campaigners, the only solution is to fly less and limit airport expansions until planes can run on genuinely renewable fuel, like electricity or possibly hydrogen.

From BBC ● Jul. 21, 2026

Most such expansions appear to be attributable to the advantages that speakers of the ancestral language, belonging to food-producing societies, held over hunter-gatherers.

From "Guns, Germs, and Steel: The Fates of Human Societies" by Jared M. Diamond

Related Words

• development
• enlargement
• extension
• increase
• inflation
• spread