1. The quality or condition of being dense. 2. The quantity of something per unit measure, especially per unit length, area, or volume. 3. The mass per unit volume of a substance under specified conditions of pressure and temperature. 4. The number of units of useful information contained within a linear dimension. 5. The number of individuals, such as inhabitants or housing units, per unit of area. 6. The degree of optical opacity of a medium or material, as of a photographic negative. 7. Thickness of consistency; impenetrability. 8. Complexity of structure or content. 9. Stupidity; dullness.
