What is the meaning of Density?

The amount of a certain phenomenon (such as stuff, things, energy, or otherwise) in a given area (surface area) or volume (amount of space).

A measure of the mass of matter contained by a unit volume.

The ratio of one quantity, representing something of interest, to another quantity representing space, area, or extent in which the thing of interest is distributed.

The probability that an outcome will fall into a given range, per unit of that range; the relative likelihood of possible values of a continuous random variable.

Stupidity.

Source: wiktionary.org