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

expansional

ik-ˈspan(t)-sh(ə-)nəl 

adjective

Synonyms

• accretion
• accrual
• addendum
• addition
• augmentation
• boost
• gain
• increase
• increment
• more
• plus
• proliferation
• raise
• rise
• step-up
• supplement
• uptick

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

Officials have been grappling with how to make the system feel safer — even as there are ambitious plans underway for a serious expansion. —Rachel Uranga, Los Angeles Times, 16 May 2024

One issue was that the continual expansion of the settlements was becoming an irritant in U.S.-Israel relations. —Mark Mazzetti Jonathan Davis Anna Diamond David Mason, New York Times, 16 May 2024

Word History

First Known Use

1611, in the meaning defined at sense 1

Phrases Containing expansion

• expansion card
• expansion slot

Kids 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 

1

: the act or process of expanding

2

: the quality or state of being expanded