expansion

American  

[ik-span-shuhn] / ɪkˈspæn ʃən /

noun

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 (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

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

Etymology

Origin of expansion

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

Example Sentences

“This significant expansion of our compute infrastructure will power our frontier Claude models and help us serve extraordinary demand from customers worldwide,” Anthropic said in a blog post on Monday.

From Barron's • Apr. 7, 2026

Thirdly, Carter pointed to the Big Ten’s recent expansion as a main driver of revenue, and subsequently of its recent success on the court and field.

From MarketWatch • Apr. 7, 2026

The charity, which supports struggling households, said the expansion at its base on Lowesmoor Wharf would give its support services a "new lease of life".

From BBC • Apr. 7, 2026

Sunway’s growth is underpinned by resilient property sales, strong contributions from unit Sunway Construction, and its continued expansion in healthcare.

From The Wall Street Journal • Apr. 7, 2026

Our lease was renewed, and my family started working with a contractor for the expansion almost immediately.

From "The Epic Fail of Arturo Zamora" by Pablo Cartaya

Related Words

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