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

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Etymology

Origin of expansion

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

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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

She recently said the expansion had created thousands of union jobs, which already paid nearly $10 million in total wages, “delivering an economic boost for Los Angeles.”

From Los Angeles Times ● Oct. 18, 2026

Last year, Reeves announced the government-backed expansion, saying "a third runway is badly needed", and the government could not "duck the decision any longer".

From BBC ● Oct. 17, 2026

Barclays maintains its 2026 economic growth forecast for Malaysia at an expansion of 5.6%, above the government’s revised estimate of 4.8%-5.3%

From The Wall Street Journal ● Oct. 16, 2026

The expansion became particularly noticeable between 2012 and 2014, when Antarctic winter sea ice set new record highs for three consecutive years.

From Science Daily ● Oct. 16, 2026

They seem to partake vigorously in the expansion of the universe, some receding from us at more than 90 percent the speed of light.

From "Cosmos" by Carl Sagan

Vast expansions in electricity, telecommunications and production promised to connect the country and ease the tedious work of cooking, washing and cleaning.

From Los Angeles Times ● Oct. 7, 2026

After a decade of acquisitions and expansions by Spencer, Sharma is cutting output and focusing on key franchises she thinks have room to grow, like “Elder Scrolls” and “Halo.”

From The Wall Street Journal ● Sep. 12, 2026

Ahead of Tesla’s event, rivals announced their own expansions.

From MarketWatch ● Sep. 2, 2026

Aggressive expansions typically come with plenty of risk: an immediate strain on resources, profit instability, and possibly outgrowing the existing business model.

From Slate ● Aug. 24, 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

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Related Words

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

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