expand

verb

ex·​pand ik-ˈspand 

expanded; expanding; expands

transitive verb

1

: to open up : unfold

2

: to increase the extent, number, volume, or scope of : enlarge

They expanded the business to serve a larger area.

3

a

: to express at length or in greater detail

b

: to write out in full

expand all abbreviations

c

: to subject to mathematical expansion

expand a function in a power series

intransitive verb

1

: to open out : spread

The universe is expanding.

2

: to increase in extent, number, volume, or scope

an expanding population

3

: to speak or write fully or in detail

—used with on or upon

expanded on the theme

4

: to feel generous or optimistic

expandability

ik-ˌspan-də-ˈbi-lə-tē 

noun

expandable

ik-ˈspan-də-bəl 

adjective

Synonyms of expand

• develop
• supplement

Choose the Right Synonym for expand

expand, amplify, swell, distend, inflate, dilate mean to increase in size or volume.

expand may apply regardless of the manner of increase (such as growth, unfolding, addition of parts).

a business that expands every year

amplify implies the extension or enlargement of something inadequate.

amplify the statement with details

swell implies gradual expansion beyond a thing's original or normal limits.

the bureaucracy swelled to unmanageable proportions

distend implies outward extension caused by pressure from within.

a distended abdomen

inflate implies expanding by introduction of air or something insubstantial and suggests a vulnerability to sudden collapse.

an inflated ego

dilate applies especially to expansion of circumference.

dilated pupils

Examples of expand in a Sentence

The liquid expands and contracts with changes in temperature.

His business has expanded to serve the entire state.

The coffee shop may expand into a full restaurant.

He has expanded his business to serve the entire state.

There are plans to expand the airport.

The police have decided to expand their investigation.

She plans to expand the lecture series into a book.

Expand the abbreviation “deg.” to “degree.”

Recent Examples on the Web

Much of her time in the legislature has been focused on expanding educational access, criminal justice reform, workplace protections, consumer protections and cleaner air. — Christa Swanson, CBS News, 8 Nov. 2026

As the hot universe expanded and cooled, nuclear reactions produced hydrogen, helium, deuterium, and small amounts of lithium. — Rupendra Brahambhatt, Interesting Engineering, 8 Nov. 2026

Frye called for policies that increase transparency around gate utilization rate, establish meaningful utilization standards and expand the number of common-use gates. — Charlotte Observer, 7 Nov. 2026

Banking consolidation belongs in that conversation because financing helps determine which developments proceed, which businesses expand and which families acquire assets. — Ed Gaskin, Boston Herald, 7 Nov. 2026

Word History

Etymology

Middle English expaunden, from Latin expandere, from ex- + pandere to spread — more at fathom

First Known Use

15th century, in the meaning defined at transitive sense 1

Phrases Containing expand

• expand on/upon

Rhymes for expand

• armband
• backhand
• bandstand
• baseband
• broadband
• command
• cropland
• demand
• disband
• dreamland
• farmhand
• farmland

Kids Definition

expand

verb

ex·​pand ik-ˈspand 

1

: to open wide : unfold

a bird with wings expanded

2

: to increase in size, number, or amount

substances expand when heated

the expanding universe

their work expanded

3

: to work out in greater detail

expand an argument

4

: to perform the indicated mathematical operations of : write out in full

expand both sides of an equation

expandable

-ˈspan-də-bəl 

adjective

expander noun