ex·​pan·​sion | \ ik-ˈspan(t)-shən How to pronounce expansion (audio) \

Definition of expansion

1 : expanse
2 : the act or process of expanding territorial expansion economic expansion expansion of the universe
3 : the quality or state of being expanded
4 : the increase in volume of working fluid (such as steam) in an engine cylinder after cutoff or in an internal combustion engine after explosion
5a : an expanded part
b : something that results from an act of expanding the book is an expansion of a lecture series
6 : the result of carrying out an indicated mathematical operation : the expression of a function in the form of a series

Other Words from expansion

expansional \ ik-​ˈspanch-​nəl How to pronounce expansion (audio) , -​ˈspan(t)-​shə-​nᵊl \ adjective

Examples of expansion in a Sentence

The league is undergoing expansion. the expansion of a lecture series into a book This book is an expansion of a lecture series.
Recent Examples on the Web Construction will begin next year on an expansion to the Windgate Building, with the new square footage to be partly used as studio space for faculty and students. From Usa Today Network And Wire Reports, USA TODAY, 14 Sep. 2022 The contract is an expansion of the program from the county’s middle schools to its elementary schools. Nicole Asbury, Washington Post, 13 Sep. 2022 Kroger announced an expansion of its private-label business on Friday, convinced that customers’ taste for cheaper options will last long into the future. The Editorial Board, WSJ, 13 Sep. 2022 The American Stories Documentary Fellowship serves as an expansion of the American Stories Documentary Fund, which was launched in 2020 and aimed to support filmmakers with projects that were in production and impacted by the COVID-19 pandemic. Abbey White, The Hollywood Reporter, 13 Sep. 2022 The 8,000-square-foot retail display and sales floor is an expansion of Aurora Mills Architectural Salvage, which has been selling architectural antiques, industrial objects and salvaged Oregon lumber since 1999 in a historic former mill. oregonlive, 13 Sep. 2022 The expansion of the Child Tax Credit helped reduce childhood poverty, as measured by the bureau's Supplemental Poverty Measure, from 9.7% in 2020 to 5.2% last year. Mike Schneider, ajc, 13 Sep. 2022 The expansion of the Child Tax Credit helped reduce childhood poverty, as measured by the bureau’s Supplemental Poverty Measure, from 9.7 percent in 2020 to 5.2 percent last year. Mike Schneider, BostonGlobe.com, 13 Sep. 2022 The Louisville distillery, which opened in 2016, just completed an $8.2 million expansion of its facilities. Jonah Flicker, Robb Report, 12 Sep. 2022 See More

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'expansion.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

First Known Use of expansion

1611, in the meaning defined at sense 1

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Time Traveler for expansion

Time Traveler

The first known use of expansion was in 1611

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Last Updated

17 Sep 2022

Cite this Entry

“Expansion.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/expansion. Accessed 28 Sep. 2022.

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More Definitions for expansion


ex·​pan·​sion | \ ik-ˈspan-shən How to pronounce expansion (audio) \

Kids Definition of expansion

: the act of growing or increasing : enlargement


ex·​pan·​sion | \ ik-ˈspan-chən How to pronounce expansion (audio) \

Medical Definition of expansion

1 : the act or process of expanding
2 : the quality or state of being expanded

More from Merriam-Webster on expansion

Nglish: Translation of expansion for Spanish Speakers

Britannica English: Translation of expansion for Arabic Speakers


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