On this program we talk about common expressions in American English – where they come from and how to use them . Today we leave the mainstream -- the majority . We go to the edge of society – to the lunatic fringe . Merriam-Webster's online dictionary defines lunatic fringe as “members of a political or social group or movement who have the most extreme or foolish ideas .” It is the radical part of a group or political party . Two other words that describe people who are part of the lunatic fringe are fanatics and zealots . But now , let's look at the word “lunatic .” Lunatics are mentally unstable people or people who behave very foolishly . The root of lunatic is “luna ,” Latin for “moon .” Now , the word “fringe ” has several meanings . For example , fringe can be a decorative border . Curtains , pillows , tablecloths and clothing are all things that can have fringe . This meaning goes back hundreds of years . Fringe can also mean to be on the outer edge of something . For example , the family lived on the fringe of a national park . This is an actual area where their property meets the park . But you can also be on the fringe of something that you can't physically touch . For example , my friend who lives in Los Angeles has worked on the fringe of the entertainment industry for many years . Fringe theater is theater that is experimental in style or subject matter . There are fringe theater festivals all over the world . One difference between fringe festivals and traditional arts festivals is the way performers are chosen . Usually , traditional festivals include a selection process . However , most fringe festivals do not . It is usually a first come , first served process . As a result , you can see some strange and different theater performances at a fringe festival . They are definitely not mainstream . The term comes from Scotland's Edinburgh Festival Fringe . According to the festival's website , it dates back to 1947 . That year , eight uninvited theater groups came to perform at the recently formed Edinburgh International Festival . They weren't part of the official festival . But this did not stop the performers . They performed on the fringe , or edge , of the official festival . That is the meaning of fringe that is part of today's expression – lunatic fringe . The Online Etymology Dictionary says that , in the late 1800s , “lunatic fringe ” described a type of hairstyle for young women . Women with this hairstyle wore their hair straight across their forehead . These days , in American English , we call the hair that falls over the forehead “bangs .” There are several examples of writers in the late 1800s using the phrase “lunatic fringe ” to mean a hairstyle . However , word historians give former President Theodore Roosevelt credit for today's meaning of “lunatic fringe .” In 1913 , shortly after a failed attempt to become president again , Roosevelt wrote about an art exhibit of painters . These artists painted in ways no one had seen before . At the time , they were the "lunatic fringe " of the art world . This paragraph is from Roosevelt's writing titled , “History as Literature .” “… we have to face the fact that there is apt to be a lunatic fringe among the votaries [loyal followers ] of any forward movement . In this recent art exhibition the lunatic fringe was fully in evidence , especially in the rooms devoted to the Cubists and the Futurists , or Near-Impressionists .” But he does get the credit for making lunatic fringe more mainstream .