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

Compact skulls were considered stronger than longer, narrower ones.

From Science Daily • May 20, 2026

The Mayflower Compact quarter includes a woman on the front.

From The Wall Street Journal • Dec. 11, 2025

Under an agreement known as the Compact of Free Association, Palau gives the US exclusive military access in exchange for Washington's extensive aid, including Palauan citizens' ability to live and work freely in the US.

From BBC • Nov. 23, 2025

As she explained, the president can only send other states’ National Guards to perform crime control when he has invoked the Emergency Management Assistance Compact.

From Slate • Nov. 21, 2025

Compact, hard, logical, totally selfish, the virus is dedicated to making copies of itself— which it can do on occasion with radiant speed.

From "The Hot Zone" by Richard Preston

Related Words

• solid
• tight