Definitions
1.adjectiveHaving relatively high density.
2.adjectiveCompact; crowded together.
3.adjectiveThick; difficult to penetrate.
4.adjectiveOpaque; allowing little light to pass through.
5.adjectiveObscure, or difficult to understand.
6.adjectiveBeing a subset of a topological space that approximates the space well. See Wikipedia article on dense sets for mathematical definition.
7.adjective(of a person) Slow to comprehend; of low intelligence.