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

Definition of expansion

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

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Other Words from expansion

expansional \ ik-​ˈspanch-​nəl How to pronounce expansional (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.
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Recent Examples on the Web The expansion was not homogeneous; over its course the mixture of fossil fuels used changed quite dramatically. The Economist, "Not-so-slow burn The world’s energy system must be transformed completely," 23 May 2020 Read how global banks are turning inward during the pandemic The overseas expansion is part of a midterm plan announced last week. Yuki Hagiwara, Bloomberg.com, "Japan’s Sumitomo Mitsui Has Hiring, Acquisition Plans Overseas," 20 May 2020 Playoff expansion was one of two topics Ohio high school football coaches considered amongst themselves. Shelby Dermer, Cincinnati.com, "OHSAA to expand football playoffs to 12 teams per region starting in 2021," 20 May 2020 The latest expansion to the world of sisters Elsa and Anna isn't another story (yet), but a making-of docuseries that goes behind the scenes of Frozen 2. Nick Romano, EW.com, "Frozen 2 making-of docuseries coming to Disney+ in June," 13 May 2020 The expansion of businesses and investments in infrastructure are the engines of growth and job creation. Rodrigo Olivares-caminal, Quartz Africa, "Africa needs to be wary of the unintended consequences with a moratorium on its debt," 11 May 2020 Intel’s long-range construction plans for Ronler Acres indicate that site will be full when the current expansion is complete. oregonlive, "Intel and TSMC consider new U.S. chip factories," 11 May 2020 Twice a Fortnite Fortnite’s ardent expansion into music entertainment is worth watching. Fortune, "Designing a safe work space for the post-pandemic era," 5 May 2020 Later, in his own consulting practice, he was involved with the Marquette Interchange freeway expansion and was project manager for the construction of the Milwaukee Public Museum’s I-Max Theater. Bill Glauber, Milwaukee Journal Sentinel, "Civil engineer Gerald Schwerm put his imprint on Brown Deer and Milwaukee County," 24 Apr. 2020

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.

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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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Statistics for expansion

Last Updated

25 May 2020

Cite this Entry

“Expansion.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/expansion. Accessed 2 Jun. 2020.

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More Definitions for expansion


How to pronounce expansion (audio)

English Language Learners Definition of expansion

: the act of becoming bigger or of making something bigger : the act of expanding
: a more complete and detailed written work or set of comments based on something shorter


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

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