What Does Dense Mean?

Dense means thick. Things that don't allow the passage of light or allows only very little light through it is known as dense. Dense things are usually compact in nature. They have components parts closely crowded together. They have high relative density and specific gravity.

Somebody who is quite foolish is also called dense as nothing goes inside his brain. Thus dense means close together or thick. But its meaning depends on the context. He is very dense means very different from this area has a dense population. The first sentence refers to the the stupidity or dumbness of a person while the second sentence indicates that there is a large concentration of people, house and automobiles in the area.

Dense does NOT mean the same thing as thick. If something is dense, it means there are more particles packed into a particular volume, and/or the particles are heavier.
Air is less dense than water because air particles are much more spread out than water particles.
Even though lead particles and water particles are roughly the same distance apart, lead is more dense than water because its particles are heavier than water particles.

Dense usually means thick and hard, or difficult, such as how dense is clay, or in the sense of an insult, means you are too dense, being difficult to penetrate intellectually, that you do not learn because you are to dense for information to get through

To be thick, tight together

Thick