the state or quality of being dense; compactness; closely set or crowded condition.

stupidity; slow-wittedness; obtuseness.

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.

Physics . mass per unit volume.

Electricity .

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.

current density.

the degree of opacity of a substance, medium, etc., that transmits light.

Photography . the relative degree of opacity of an area of a negative or transparency, often expressed logarithmically.

Computers . a measure of the compactness of data stored on an external storage medium, as disk or tape, or displayed on a CRT or other screen.

noun

openness , sparsity , thinness

noun

body , closeness , compactness , concretion , consistency , crowdedness , denseness , frequency , heaviness , impenetrability , massiveness , quantity , solidity , substantiality , thickness , tightness , bulk , complexity , mass , weight