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

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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.
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Recent Examples on the Web The Vezina Trophy finalist went from Stanley Cup favorite Colorado to an expansion team. Mike Brehm, USA TODAY, 28 July 2021 On defense, the Bruins’ replacement for Seattle expansion draft loss Jeremy Lauzon is Derek Forbort, according to multiple reports. BostonGlobe.com, 28 July 2021 Svechnikov was placed on waivers again in April, and exposed in July’s expansion draft. Helene St. James, Detroit Free Press, 26 July 2021 After building a 32-14 halftime lead, the Pirates, an expansion team, had a season-high for points in a game through the first three quarters, scoring 54. Richard Obert, The Arizona Republic, 18 July 2021 Colangelo was the Suns' first general manager when the organization entered the league as an expansion team in 1968. Brian Mahoney, Star Tribune, 14 July 2021 On each seat, the promoters left a questionnaire gauging potential support for an NBA expansion team — not an exhibition game or minor-league team, but a full-time franchise based in Anchorage. David Reamer, Anchorage Daily News, 11 July 2021 The same year Tepper bought the Panthers, the NHL’s newest hockey team, the Las Vegas Golden Knights, accomplished what only one expansion team had done before by making it to the league finals in its inaugural season. Robert Faturechi, ProPublica, 8 July 2021 Part of the challenge for any expansion team is managing expectations. Tim Sullivan, The Courier-Journal, 5 July 2021

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

31 Jul 2021

Cite this Entry

“Expansion.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/expansion. Accessed 3 Aug. 2021.

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More Definitions for expansion



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

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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