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

In fact, the Portsmouth study found that bone density could not predict whether someone could float.

From BBC ● Aug. 31, 2026

“In my opinion, we are operating at the maximum density that can be safely operated,” said Jonathan McDowell, an astrophysicist who maintains a widely cited catalog of objects in space.

From The Wall Street Journal ● Aug. 30, 2026

A gravimeter can detect differences in density, allowing researchers to distinguish the denser surrounding rock from the much lighter buried ice.

From Science Daily ● Aug. 28, 2026

Depending on this density, the water was determined to be either Atlantic or polar in origin.

From Barron's ● Aug. 26, 2026

For convenience, Hutton had assumed that the mountain had the same density as ordinary stone, about 2.5 times that of water, but this was little more than an educated guess.

From "A Short History of Nearly Everything" by Bill Bryson

As the flow of gas from the cosmic web becomes weaker and gas densities decrease, galaxies may become less efficient at converting HI into molecular hydrogen.

From Science Daily ● Sep. 3, 2026

With characteristic densities near 10-6 Mpc-3, those objects would contribute substantially less to the observed signal.

From Science Daily ● Aug. 27, 2026

In dwarf galaxies, the process creates dark matter cores with relatively low central densities, matching recent observations of galaxy clustering.

From Science Daily ● Jul. 14, 2026

The behavior of matter compressed to such extraordinary densities remains poorly understood, leaving open the possibility of new physical phenomena.

From Science Daily ● Jun. 14, 2026

Briefly, at high population densities only a portion of the people came to be farmers, but they were mobilized to devote themselves to intensive food production, thereby yielding surpluses to feed nonproducers.

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

Related Words

• frequency
• quantity
• thickness