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

Mining and refining minerals is highly energy-intensive, meaning that any expansion of production will require massive investments in rebuilding power infrastructure. —Dan Perry, Newsweek, 28 Feb. 2025

Civil rights attorney Benjamin Crump is calling for the expansion of crisis intervention programs as new data shows police killings hit a record high in 2024 — despite a national decline in violent crime. —Delano Massey, Axios, 28 Feb. 2025

The Virgo lunar eclipse on March 14th lights up your sector of expansion and adventure. —Dossé-Via Trenou, refinery29.com, 27 Feb. 2025

Her approach and deep industry experience of global expansion and storytelling will bring our growth strategy to new heights. —Matt Grobar, Deadline, 27 Feb. 2025

Word History

First Known Use

1611, in the meaning defined at sense 1

Phrases Containing expansion

• expansion card
• expansion slot

Rhymes for expansion

• mansion
• scansion

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