Let $A$ be a nowhere dense set, what is the name of $A^c$? It seems much stronger than the definition of dense set. I think if we assume $A$ is a close set, then $A$ is nowhere dense iff $A^c$ is dense. But what about the general case?
I found a long name for this: a dense set with dense interior. Does there exist a fancier name, probably named after a person?
A nowhere dense set is one whose closure has an empty interior.
Therefore the complement of a nowhere dense set is one whose interior has a closure that is the entire space.
Or, in other words, a set whose interior is dense.
Or, in yet other words, a superset of a dense open set.