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

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

Researchers found that greater reductions in energy density were tied to lower calorie intake and greater weight loss, despite the absence of any instructions to eat less.

From Science Daily ● Aug. 17, 2026

A low-fat vegan diet can reduce the energy density of the foods people eat by about 30%, helping them consume fewer calories while still eating satisfying amounts of food.

From Science Daily ● Aug. 17, 2026

Accurately measuring atmospheric density at these heights is therefore important for forecasting satellite motion and reducing the risk of collisions.

From Science Daily ● Aug. 12, 2026

Shenandoah is said to have the highest density of black bears anywhere in the world—slightly over one per square mile.

From "A Walk in the Woods" by Bill Bryson

At extremely high densities, quantum effects can generate powerful pressure that prevents matter from being compressed without limit.

From Science Daily ● Aug. 11, 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

They reach their greatest densities in the UK's woods where many thousands of bulbs can exist in one woodland, creating the incredible blue carpets associated with spring.

From BBC ● May 10, 2026

Where population densities are moderate, as in regions occupied by food-producing tribes, no large vacant areas remain to which survivors of a defeated band can flee.

From "Guns, Germs, and Steel: The Fates of Human Societies" by Jared M. Diamond

Related Words

• frequency
• quantity
• thickness