expansion
noun
ex·pan·sion
ik-ˈspan(t)-shən 
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
5
a
: 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
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
Chinese Premier Li Qiang has reiterated the need to boost non-fossil energy expansion and to build a new energy system, while encouraging innovation and quicker reforms, the research organization said.
—
Justina Lee,
CNBC,
6 July 2026
The only blot on an otherwise solid opening week for the World Cup expansion loyalists.
—
Anantaajith Raghuraman,
New York Times,
5 July 2026
That is also reflected in our recent expansion beyond Bermuda to destinations including Anguilla, Turks and Caicos, Belize and Grand Cayman.
—
Ramsey Qubein,
Forbes.com,
5 July 2026
Playhouse on Park often has to scale down large musicals for its 160-seat theater, but in this case the close-up party atmosphere feels like an expansion.
—
Christopher Arnott,
Hartford Courant,
5 July 2026
See All Example Sentences for expansion
Examples are automatically compiled from online sources to
show current usage.
Read More
Opinions expressed in the examples do not represent those of Merriam-Webster or its editors.
Send us feedback.
Justina Lee,
CNBC,
6 July 2026
The only blot on an otherwise solid opening week for the World Cup expansion loyalists.
—
Anantaajith Raghuraman,
New York Times,
5 July 2026
That is also reflected in our recent expansion beyond Bermuda to destinations including Anguilla, Turks and Caicos, Belize and Grand Cayman.
—
Ramsey Qubein,
Forbes.com,
5 July 2026
Playhouse on Park often has to scale down large musicals for its 160-seat theater, but in this case the close-up party atmosphere feels like an expansion.
—
Christopher Arnott,
Hartford Courant,
5 July 2026
See All Example Sentences for expansion
Cite this Entry
“Expansion.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/expansion. Accessed 6 Jul. 2026.
Copy CitationKids Definition
expansion
noun
ex·pan·sion
ik-ˈspan-chən
1
: the act of expanding
2
: the state of being expanded
3
: something expanded or a result of expanding
4
: the result of carrying out indicated mathematical operations
the expansion of (a + b)2 is a2 + 2ab + b2
Medical Definition
expansion
noun
ex·pan·sion
ik-ˈspan-chən
Love words? Need even more definitions?
Merriam-Webster unabridged
