compact

¹ American  

[kuhm-pakt, kom-, kom-pakt, kuhm-pakt, kom-pakt] / kəmˈpækt, kɒm-, ˈkɒm pækt, kəmˈpækt, ˈkɒm pækt /

adjective

1. joined or packed together; closely and firmly united; dense; solid.

   compact soil.

2. arranged within a relatively small space.

   a compact shopping center;

   a compact kitchen.

   Synonyms:

   snug, small

3. designed to be small in size and economical in operation.

4. solidly or firmly built.

   the compact body of a lightweight wrestler.

5. expressed concisely; pithy; terse; not diffuse.

   a compact review of the week's news.

   Synonyms:

   brief, succinct, concise

6. composed or made (usually followed byof ).

   a book compact of form and content.

7. Mathematics. Also (of a set) having the property that in any collection of open sets whose union contains the given set there exists a finite number of open sets whose union contains the given set; having the property that every open cover has a finite subcover.

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verb (used with object)

compacts, present (3rd person singular) compacted, past participle, past compacting present participle

1. to join or pack closely together; consolidate; condense.

   Synonyms:

   compress

2. to make firm or stable.

   Synonyms:

   solidify, stabilize

3. to form or make by close union or conjunction; make up or compose.

4. Metallurgy. to compress (metallic or metallic and nonmetallic powders) in a die to be sintered.

5. to crush into compact form for convenient disposal or for storage until disposal.

   to compact rubbish.

noun

1. a small case containing a mirror, face powder, a puff, and sometimes rouge.

2. Also called compact car.  an automobile that is smaller than an intermediate but larger than a subcompact and generally has a combined passenger and luggage volume of 100–110 cu. ft. (2.8–3.1 m3 ).

3. Metallurgy. (in powder metallurgy) an object to be sintered formed of metallic or of metallic and nonmetallic powders compressed in a die.

compact ² American  

[kom-pakt] / ˈkɒm pækt /

noun

1. a formal agreement between two or more parties, states, etc.; contract.

   the proposed economic compact between Germany and France.

   Synonyms:

   concordat, convention, entente, pact, treaty

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compact ¹ British  

adjective

1. closely packed together; dense

2. neatly fitted into a restricted space

3. concise; brief

4. well constructed; solid; firm

5. (foll by of) composed or made up (of)

6. denoting a tabloid-sized version of a newspaper that has traditionally been published in broadsheet form

7. logic (of a relation) having the property that for any pair of elements such that a is related to b, there is some element c such that a is related to c and c to b, as less than on the rational numbers

8. (of a car) small and economical

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verb

1. to pack or join closely together; compress; condense

2. (foll by of) to create or form by pressing together

   sediment compacted of three types of clay

3. metallurgy to compress (a metal powder) to form a stable product suitable for sintering

noun

1. a small flat case containing a mirror, face powder, etc, designed to be carried in a woman's handbag

2. a comparatively small and economical car

3. metallurgy a mass of metal prepared for sintering by cold-pressing a metal powder

4. a tabloid-sized version of a newspaper that has traditionally been publis hed in broadsheet form

compact ² British  

/ ˈkɒmpækt /

noun

1. an official contract or agreement

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Synonym Usage

See agreement.

Other Word Forms

Derived Forms

• compactedness
  noun
• compacter
  noun
• compaction
  noun
• compactness
  noun
• uncompacted
  adjective
• well-compacted
  adjective
• compactedly
  adverb
• compactly
  adverb

Inflected Forms

Participles

• compacting
  present
• compacted
  past

Conjugated Forms

Present

• compact
  simple
• compacts
  simple
• have compacted
  perfect
• has compacted
  perfect
• am compacting
  progressive
• are compacting
  progressive
• is compacting
  progressive
• have been compacting
  perfect progressive
• has been compacting
  perfect progressive

Past

• compacted
  simple
• had compacted
  perfect
• was compacting
  progressive
• were compacting
  progressive
• had been compacting
  perfect progressive

Future

• will compact
  simple
• will have compacted
  perfect
• will be compacting
  progressive
• will have been compacting
  perfect progressive

Etymology

Origin of compact¹

First recorded in 1350–1400; Middle English, from Latin compāctus (past participle of compingere “to shut away, put away, bind together”), equivalent to com- prefix + pag-, stem of pangere “to fix, arrange” + -tus past participle suffix; see com-; cf. peace; pact, compact ² )

Origin of compact²

First recorded in 1550–60; from Latin compactum, compectum, noun use of neuter of compactus (past participle of compacīscī “to make an agreement”), equivalent to com- prefix + pac- (stem of pacīscī “to secure by negotiation” + -tus past participle ending); see com-; cf. compact ¹, pact, peace

Explanation

A compact is a signed written agreement that binds you to do what you've promised. It also refers to something small or closely grouped together, like the row of compact rental cars you see when you wanted a van. As a verb, compact means "to compress or squeeze together," like how the garbage truck compacts your bags of trash. Compact, the adjective, describes something that is tightly packed together, like your luggage that is so compact it fits in the overhead compartment. Compact can also describe a brief summary, like a compact explanation of how the universe began that lasted only 10 minutes!

Example Sentences

See Examples For:

compact compacts compacted compacting

Because they are so compact, a Dyson swarm could orbit just a few million kilometers above the star's surface, dramatically reducing the scale of the structure needed.

From Science Daily ● Jul. 10, 2026

Upon awarding the prize, a member of the Nobel committee likened the technology’s ability to store enormous amounts of stuff in seemingly compact spaces to Hermione Granger’s enchanted handbag in the Harry Potter series.

From Los Angeles Times ● Jul. 10, 2026

Marshall Islands achieved independence in 1986, and continues to have a defence compact with the United States that allows missile tests on its territory.

From Barron's ● Jul. 9, 2026

Gildas, as Mr. Higham relates, likened post-Roman Britain to ancient Israel, exhorting his countrymen to “renew their compact with God and thereby recover His favor and, in consequence, their ancestral homeland.”

From The Wall Street Journal ● Jul. 7, 2026

Olka panicked and pulled a compact from her purse.

From "Not Nothing" by Gayle Forman

Multiple states have gone to court to argue prediction markets are nothing more than unlicensed gambling sites that operate in violation of state law and tribal compacts.

From Los Angeles Times ● Feb. 1, 2026

I hope we’ll move beyond defensiveness and talk of federal compacts and instead take action.

From The Wall Street Journal ● Jan. 25, 2026

By design, the details of how "freedom cities" would be established are laden with legalese like "federal enclaves with special economic and jurisdictional zones" or "interstate compacts."

From Salon ● Mar. 17, 2025

“The social compacts that the people have sown in them are very ingrained.”

From Seattle Times ● May 28, 2024

Kaz had told her to keep an eye out for women using similarly made mirrored compacts at the Crow Club.

From "Six of Crows" by Leigh Bardugo

Even the design of farm machinery was considered — and tractors were fitted with wider tires to ensure that soil was less compacted when driven over.

From The Wall Street Journal ● Jun. 23, 2026

Firn is partially compacted granular snow found near the upper portions of glaciers.

From Science Daily ● Jun. 12, 2026

The soil was so compacted that each time they dug a planting hole, it took an hour to drain.

From Los Angeles Times ● Oct. 15, 2025

These layers of ice, compacted over centuries, perhaps millennia, form an archive of climate indicators, yielding data on past snowfall, temperatures, atmosphere and dust.

From Barron's ● Oct. 13, 2025

We walked over the compacted dirt toward the entrance, which wasn’t closed up, even though the park wasn’t open yet—I guess they weren’t too worried about people sneaking in.

From "Insignificant Events in the Life of a Cactus" by Dusti Bowling

A digger methodically spread it out, compacting it as it worked.

From BBC ● Feb. 25, 2025

And because the ice is stable, the thick annual layers can accumulate for centuries, compacting into ice.

From Science Magazine ● Apr. 18, 2024

However, there are also many disadvantages of compacting your lifestyle into a space not much bigger than a motel room.

From Seattle Times ● Feb. 19, 2024

Deep in Antarctica’s frigid interior, fluffy, air-filled snow accumulates layer by layer, compacting into slabs of ice over millennia.

From Scientific American ● Feb. 9, 2023

After picking for two long hours, Roberto helped Mama make more room in her sack by lifting it upright and shaking it several times up and down, compacting the cotton to the bottom.

From "The Circuit: Stories from the Life of a Migrant Child" by Francisco Jiménez

Related Words

• solid
• tight