Pagan is a word that has been used in a derogatory manner in the past to refer to those who were not Christian or who did not behave in a manner Christians believed to be appropriate. It has since been “reclaimed” by a specific group of people who are perfectly happy not to be Christian or approved of by Christians.
One prevailing theory about the origin of the word Pagan comes from the Latin Paganus meaning “country dweller”, along the lines of the modern terms “hick” or “hillbilly”. These folks live outside the city and don’t keep up with the fashions of the elite and so might seem backward or strange to city folk. In ancient Rome, religion was one of these fashions and that is how the word Pagan came to be applied to non-mainstream religions.
Another popular theory is that the word paganus meant “civilian”, that is, not part of the military. According to this theory, Christians referred to themselves as “miles Christi” or “soldiers of Christ”. Thus, non-Christians were called “paganus” as they were decidedly not soldiers of Christ.
In a modern context, the word Pagan is often used to describe any religion that isn’t part of the Judeo-Christian family of religions and in many cases, it is used in a derogatory sense to imply Satan worship. However, many Pagans will point out that Satan is a being that is defined according to the Judeo-Christian worldview and therefore anyone who worships Him is by this definition not Pagan. It also is perhaps limiting to define Paganism as simply “Not Judeo-Christian” as many would disagree that Hinduism or Buddhism are Pagan, certainly many ethnic Hindus, and Buddhists. Thus, another definition presents itself, still in line with the history of the word: A follower of a religion other than that which is approved by the greater social culture of the area.
In different circles, the word Pagan is used to describe Earth based spirituality specifically while others use the word Pagan to describe magico-religious tradition, the word Pagan has become synonymous with spiritual Witchcraft in many circles. It is also used to mean polytheism, both modern and ancient.
Other Definitions on the Web
Oh his blog, Ian Corrigan defines Pagan http://intothemound.blogspot.com/2013/11/the-authority-of-paganism.html
At allAboutSpirituality.org https://www.allaboutspirituality.org/paganism.htm
Defining Paganism by Isaac Bonewits http://www.neopagan.net/PaganDefs.html