Xingu

A group of six women engage in a Lunch Club with the point of basically being as pretentious as possible.  A tale of the women who belong to a book club, and their attitudes toward society, each other, and most importantly...themselves. There is an unforgettable character here...Mrs. Ballinger. You will never forget her interactions with the group, and with herself.
A famous author who they have all read, all but Mrs. Roby who is the outcast of the group, comes to one of their Lunch Club meetings.  Osric Dane, the author, is so pretentious, so condescending, that she totally throws these polite, stuck up women off their game.
Mrs. Roby saves the day by bringing up the concept of Xingu, which the other women pretend to know all about but really have no clue what she is talking about.  Mrs. Roby puts Osric Dane in her place, and leaves, with Osric begging to join her. 
The other women are very taken aback and begin to argue with each other about Xingu, which they still have no idea what it is.  By Edith Wharton.