Arthur Chu (Who? Apparently somebody who once did well on Jeopardy), who apparently believes that he has something to say, and that everyone will listen, defines privileged as follows:
Mansplaining, whitesplaining, richsplaining—the way you can tell someone who’s 'privileged' is the unconscious belief that they have something to say, and that everyone will listen.
It turns out that his article, in The Daily Beast, is mostly about the supposedly deep links between Game of Thrones, Colonial privilege, and feminism, but I'm not really interested in that. I'm more interested in the quote, which I regard as complete bullshit. The feeling that we have something to say, and that people ought to listen, is not some freak of "privilege", but intrinsic to our human nature. Evolution went to a lot of trouble to develop our ability to speak, and our desire to share our thoughts with others.
Terms like "mansplaining", "whitesplaining" and so forth are not actually very descriptive. Instead they are ways of dismissing an argument without actually confronting it. As such, they are lazy and generally obtuse. They are also intrinsically racist and sexist - which is likely a poor strategy if you want to attack racism and sexism.