The terms Average Joe, Ordinary Joe, John Doe, Joe Sixpack (for males) and Ordinary or Average Jane (for females), are used primarily in the United States to refer to the average American. Please see http://en.wikipedia.org/wiki/Average_Joe.

A plain person. Joe is a common name, I went to two different high schools and in the first I knew 4 people named Joe. In the second, I knew 7 people named Joe. To say your average Joe, is to say an average person with nothing too special in particular.

Someone that is not very special because they are just like everyone else. So just an average or typical person. Does that help?

thank you!! Supongo que en español es como decir : fulano de tal

Joe is a very common name in England. So average Joe = anybody