# density

## noun

den·​si·​ty
plural densities
1
: the quality or state of being dense
measures of traffic density
the density of the cake
felt that the candidate's density on the subject of equality was alarming
the density of her prose
2
mathematics : the quantity per unit of volume (see volume entry 1 sense 2), unit of area (see area sense 1), or unit of length: such as
a
chemistry : the mass (see mass entry 2 sense 1c) of a substance per unit of volume
pure iron has a density of 7.8 grams per cubic centimeter
b
chemistry : the distribution of a quantity (such as electricity or energy) per unit usually of space (such as length, area, or volume)
The drawback to using ethanol as a complete replacement for gasoline, however, is not only the high cost of its production from cellulose but also its lower energy density.John R. Regalbuto
c
: the average number of individuals or units per unit of space
a population density of 500 per square mile
a housing density of 10 houses per acre
3
physics
a
: the degree of opacity (see opacity sense 2) of a translucent medium
the fog's density
b
: the common logarithm of the opacity

## Examples of density in a Sentence

We were surprised by the fog's density. the density of her writing style These instruments are used for measuring the density of the atmosphere.
Recent Examples on the Web The pricing equation now includes things like density: the Postal Service's need to deliver less mail — but to more addresses. Bill Chappell, NPR, 12 Apr. 2024 Gender-affirming medical does come with risks, according to the Endocrine Society, including impacts to bone mineral density, cholesterol levels, and blood clot risks. Kiara Alfonseca, ABC News, 11 Apr. 2024

These examples are programmatically compiled from various online sources to illustrate current usage of the word 'density.' Any opinions expressed in the examples do not represent those of Merriam-Webster or its editors. Send us feedback about these examples.

## Word History

Etymology

see dense

First Known Use

1598, in the meaning defined at sense 1

Time Traveler
The first known use of density was in 1598

density

## Cite this Entry

“Density.” Merriam-Webster.com Dictionary, Merriam-Webster, https://www.merriam-webster.com/dictionary/density. Accessed 23 Apr. 2024.

## Kids Definition

density

noun
den·​si·​ty
plural densities
1
: the quality or state of being dense
2
: the quantity of something per unit volume, unit area, or unit length: as
a
: the mass of a substance per unit volume
density expressed in grams per cubic centimeter
b
: the average number of individuals or units in a unit of area or volume
a population density of 500 per square mile

## Medical Definition

density

noun
den·​si·​ty
plural densities
1
: the quantity per unit volume, unit area, or unit length: as
a
: the mass of a substance per unit volume
b
: the distribution of a quantity (as mass, electricity, or energy) per unit usually of space
c
: the average number of individuals or units per space unit
a population density of 500 per square mile
2
a
: the degree of opacity of a translucent medium
b

## More from Merriam-Webster on density

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