The term MesoPagan was first put forth by Isaac-Bonewits in an attempt to categorize modern Paganism.
According to Bonewits, MesoPagan religions developed from PaleoPagan or native Pagan religions that were influenced by Monotheistic, dualistic or Nontheistic philosophies.
These include all syncretic religions including Christo-Paganism, many Afro-Diasporic faiths, such as Voodoo, Santeria and Candomble.
Also Sikhism and many occult traditions including Thelema, Freemasonry, Rosicrucianism, Theosophy and Spiritualism and many modern Witchcraft traditions, including many Wiccan denominations.
Also, some Satanic traditions could fall into this category.
The definition of MesoPaganism is nearly identical with that of syncretism, a word that enjoys common use in academic circles, when it is applied to any Pagan religion.
See also PaleoPaganism, Neo-Paganism
Defining Paganism: Paleo-, Meso-, and Neo- by Isaac Bonewits