Density

n. compactness, closeness

In physics, density is mass m per unit volume V—how heavy something is compared to its size. A small, heavy object, such as a rock or a lump of lead, is denser than a lighter object of the same size or a larger object of the same weight, such as pieces of cork or foam.For the common case of a homogeneous substance, density is expressed as: where, in SI Units:ρ (rho) is the density of the substance, measured in kg·m–3m is the mass of the substance, measured in kgV is the volume of the substance, measured in m³
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Noun
1. the amount per unit size
(synonym) denseness
(hypernym) compactness
(hyponym) relative density
2. the spatial property of being crowded together
(synonym) concentration, denseness, compactness
(hypernym) spacing, spatial arrangement
(hyponym) bits per inch, bpi

(n.)
The ratio of mass, or quantity of matter, to bulk or volume, esp. as compared with the mass and volume of a portion of some substance used as a standard.
  

(n.)
The quality of being dense, close, or thick; compactness; -- opposed to rarity.
  

(n.)
Depth of shade.
  

In a facsimile system, a measure of the light transmission or reflection properties of an area of an object. (188 ) Note 1: Density is usually expressed as the logarithm to the base 10 of the ratio of incident to transmitted or reflected irradiance. Note 2: There are many types of density, such as diffuse, double diffuse, and specular density, each of which will usually have different numerical values for different materials. The relevant type of density depends on the type of optical system, the component materials of the object, and the surface characteristics of the object.