An excesselively miserly person.
Despite common opinion, it does not refer to people with darker skin.
In fact the most well-known niggard was/is white!
See niggardly, niggardliness.
Person With a Small Vocabulary: WHAT'D YOU JUST CALL ME?!
Person With a Large Vocabulary: I called you a niggard. You know: stingy, not generous, generally not the kind of person you'd want to hang out with.
Person With a Small Vocabulary: Now you're just being racist!