density

American  

[den-si-tee] / ˈdɛn sɪ ti /

noun

• densities
  plural

1. the state or quality of being dense; compactness; closely set or crowded condition.

2. stupidity; slow-wittedness; obtuseness.

3. the number of inhabitants, dwellings, or the like, per unit area.

   The commissioner noted that the population density of certain city blocks had fallen dramatically.

4. Physics. mass per unit volume.

5. Electricity.

   1. the quantity of electricity per unit of volume at a point in space, or the quantity per unit of area at a point on a surface.

   2. current density.

6. the degree of opacity of a substance, medium, etc., that transmits light.

7. Photography. the relative degree of opacity of an area of a negative or transparency, often expressed logarithmically.

8. Computers. a measure of the compactness of data saved on a storage medium, as disk or tape, or displayed on an electronic screen.

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density British  

/ ˈdɛnsɪtɪ /

noun

1. the degree to which something is filled, crowded, or occupied

   high density of building in towns

2. obtuseness; stupidity

3.  ρ.  a measure of the compactness of a substance, expressed as its mass per unit volume. It is measured in kilograms per cubic metre or pounds per cubic foot See also relative density

4. a measure of a physical quantity per unit of length, area, or volume See charge density current density

5. physics photog See transmission density reflection density

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density Scientific  

/ dĕn′sĭ-tē /

1. A measure of the quantity of some physical property (usually mass) per unit length, area, or volume (usually volume).

2. ◆ Mass density is a measure of the mass of a substance per unit volume. Most substances (especially gases such as air) increase in density as their pressure is increases or as their temperature decreases.

3. ◆ Energy density is a measure of the amount of energy (often in the form of electromagnetic radiation) per unit volume in a region of space or some material.

4. See also Boyle's law

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density Cultural  

1. The relative heaviness of objects, measured in units of mass or weight per units of volume. (See specific gravity.)

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Other Word Forms

Derived Forms

• nondensity
  noun
• superdensity
  noun

Inflected Forms

Nouns

• densities
  plural

Etymology

Origin of density

First recorded in 1595–1605; from Latin dēnsitās, equivalent to dēns(us) dense + -itās -ity

Explanation

Density describes how compact or concentrated something is. For example, suppose you have two boxes, one large and one small. However, they both weigh the same. That means the small box has a higher density than the large box. Density also tells how concentrated or crowded something is. You may have heard of population density. In a city, there are many people packed into a small area, giving it a high population density. In a rural area, there are more fields or wooded areas between houses. That means there are fewer people living in a larger area, which is why it has a low population density.

Example Sentences

See Examples For:

density densities

Ignition density was highest within 50 meters of roads, although fires that started near roads were, on average, smaller than those that started farther away, the study found.

From Los Angeles Times ● Aug. 18, 2026

As 800V systems become more standardized, competition is expected to center on cost, efficiency, power density and supply reliability, Yao says.

From The Wall Street Journal ● Aug. 18, 2026

The findings suggest that a low-fat vegan diet can substantially reduce dietary energy density, allowing people to consume fewer calories and lose weight without intentionally restricting their calorie intake.

From Science Daily ● Aug. 17, 2026

Gaspar said District 3 is already doing its part to bring in new housing development in areas like Warner Center, and he remains skeptical of increasing density in single-family home neighborhoods.

From Los Angeles Times ● Aug. 17, 2026

He liked the word—its smallness, its density, the way it rose up at the end as if it had wings.

From "Flora & Ulysses: The Illuminated Adventures" by Kate DiCamillo

Astronomers have identified two of the fluffiest giant planets ever discovered, with densities so low they are actually less dense than cotton candy.

From Science Daily ● Jun. 27, 2026

By analyzing its glow, the team created the most detailed maps ever produced of temperatures and charged particle densities within Saturn's auroral region.

From Science Daily ● May 29, 2026

“With Empower we are further expanding our portfolio to help customers rearchitect their power systems and achieve the compute densities next-generation AI demands.”

From Barron's ● May 20, 2026

"There have been videos of people on cargo vessels that were going through high densities of humpback whales," she told AFP.

From Barron's ● May 11, 2026

Low-mass black holes could form only if matter was compressed to enormous densities by very large external pressures.

From "A Brief History of Time: And Other Essays" by Stephen Hawking

Related Words

• frequency
• quantity
• thickness