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

The chain eventually expanded to other nameplates — Banana Republic and Old Navy — and now generates more than $15 billion in sales globally. —Anne D'innocenzio, Chicago Tribune, 5 May 2026

That means expanding the Renter’s Tax Credit, protecting homeowners from rising costs and making sure renters know their rights and can access homelessness prevention services. —Kaitlyn Schallhorn, Oc Register, 4 May 2026

This year, leaders came together, across sectors and perspectives, to make meaningful strides in expanding access to childcare. —Franklyn Baker, Baltimore Sun, 4 May 2026

Tee times were moved up because of weather concerns, and the groups were expanded from twosomes to threesomes. —Noah Gulley, Miami Herald, 4 May 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