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

For 2025, industry experts predict expansions on already-booming product and treatment themes within the skin-care space. —Victoria Moorhouse, Allure, 12 Dec. 2024

On Israel, the bill, among other things, includes an expansion of U.S. joint military exercises with Israel and a prohibition on the Pentagon citing casualty data from Hamas. —Kevin Freking, Los Angeles Times, 11 Dec. 2024

The company is in talks with private equity firms to support Therme's continued global expansion, the CEO says. —Richard Collings, Axios, 11 Dec. 2024

Additionally, Legendary recently bought out the remaining equity interest held by Wanda Group, leaving the company solely owned by management and Apollo and launching a new phase of strategic expansion. —Dade Hayes, Deadline, 11 Dec. 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