n. pl. den·si·ties 1. The quality or condition of being dense.
2. a. The quantity of something per unit measure, especially per unit length, area, or volume.
b. The mass per unit volume of a substance under specified conditions of pressure and temperature.
3. Computers A measure of the number of bits that can be stored in a given amount of physical space on a storage medium.
4. The number of individuals, such as inhabitants or housing units, per unit of area.
5. The degree of optical opacity of a medium or material, as of a photographic negative.
6. Thickness of consistency; impenetrability.
7. Complexity of structure or content.
8. Stupidity; dullness.