"The liar uses the valid designations, the words, to make the unreal appear as real; he says, for example, 'I am rich,' when the word 'poor' would be the correct designation of his situation." ~ Friedrich Nietzsche
The common application of the word 'rich' is a term that describes a person's relative financial status compared to other people in his or her immediate environment. For example, a poor person in America may be considered rich in a third world country. Rich, therefore, is a classification or designation adopted by the conventions of a given group or society.
Financial wealth is more of a perceived state than a real one. The true goal for many people is to appear rich. If, for example, you see a person wearing expensive clothing, driving an expensive car and living in an expensive house, they appear rich. The reality may be that their sense of self is so small that they must project a large physical representation of self. Therefore this person must earn and/or borrow more money to meet and exceed the conventional meaning of rich. In my personal view, this reveals the true nature of the person: They are not rich, they are poor.
"And, moreover, what about these conventions of language? Are they really the products of knowledge, of the sense of truth? Do the designations and things coincide? Is language the adequate expression of all realities?" ~ Friedrich Nietzsche
Rich, in my humble opinion, is a person who may acknowledge the conventional meaning of the word but does not ascribe to it. In other words, a truly rich person is equally content with any amount of material wealth, assuming this amount is at least enough to purchase what is required to meet the basic physiological needs of food, shelter and clothing.
What is your definition of rich?