den·​si·​ty | \ ˈden(t)-sə-tē \
plural densities

Definition of density

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 volume (see volume entry 1 sense 2), unit area (see area sense 1), or unit length: such as
a chemistry : the mass (see mass entry 2 sense 1c) of a substance per unit volume
b chemistry : the distribution of a quantity (such as mass, electricity, or energy) per unit usually of space (such as length, area, or volume)
c : the average number of individuals or units per space unit 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

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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.
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Recent Examples on the Web

Finding materials that increase the density of lithium is one way to increase battery capacity. Chris Lee, Ars Technica, "High-density lithium in graphene: An intriguing battery possibility," 29 Nov. 2018 After all, union density is a central part of organizing efforts. Philip Bump, Washington Post, "The Supreme Court is poised to deal a sharp blow to the labor movement," 26 Feb. 2018 While the particles of the corona are indeed superheated, the density of the particles is so low that the probe's heat shield will reach temperatures of only 2,500 degrees F. Jay Bennett, Popular Mechanics, "The New Science of the Sun Will Be Astounding—And Possibly Terrifying," 9 Aug. 2018 The final phase next year will focus on UAS operations in higher-density urban areas for tasks such as news-gathering and package delivery; the FAA does not currently permit drones to be flown over crowds. Larry Greenemeier, Scientific American, "Here's What's Needed for Self-Flying Taxis and Delivery Drones to Really Take Off," 15 May 2018 That’s why the company is currently testing its technology in a few high-density urban areas including Austin and San Francisco. Johana Bhuiyan, Recode, "Alphabet will operate a fleet of 20,000 Jaguar cars for its driverless ride-hail service by 2022," 27 Mar. 2018 Council member Andrew Cripe said the village should investigate making higher density residential development possible, particularly in the downtown area. Kathy Routliffe,, "Winnetka Council members suggest higher density development to keep empty-nesters," 15 Feb. 2018 The horsetrading on how this property will be used is only just starting, Nelson said, offering up a couple of possible density-for-commercial-footage swaps. Lauren Ritchie,, "With development looming, Tangerine residents see the future, and they don't like it," 9 Feb. 2018 Slat’s device, a high-density polyethylene pipe, travels with the wind, waves, and storms and sweeps up plastic along the way. Tabor Wordelman, Teen Vogue, "You Can't Just "Clean Up" the Plastic in the Ocean. Here's Why.," 18 Dec. 2018

These example sentences are selected automatically from various online news sources to reflect current usage of the word 'density.' Views expressed in the examples do not represent the opinion of Merriam-Webster or its editors. Send us feedback.

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First Known Use of density

1598, in the meaning defined at sense 1

History and Etymology for density

see dense

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Statistics for density

Last Updated

21 Jan 2019

Look-up Popularity

Time Traveler for density

The first known use of density was in 1598

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More Definitions for density


den·​si·​ty | \ ˈden-sə-tē \
plural densities

Kids Definition of density

1 : the condition of having parts that are close together the jungle's density
2 : the amount of something in a specified volume or area high population density


den·​si·​ty | \ ˈden(t)-sət-ē, -stē \
plural densities

Medical Definition of density

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
2a : the degree of opacity of a translucent medium

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Comments on density

What made you want to look up density? Please tell us where you read or heard it (including the quote, if possible).


to gather or build up little by little

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