/den"si tee/ , n. , pl. densities .
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.
a. 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.
b. See current density .
6. the degree of opacity of a substance, medium, etc., that transmits light.
7. Photog. 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 stored on an external storage medium, as disk or tape, or displayed on a CRT or other screen.
[ 1595-1605; densitas, equiv. to dens ( us ) DENSE + -itas -ITY ]