1. The union (or attempted fusion) of different systems of thought or belief (especially in religion or philosophy)
   "a syncretism of material and immaterial theories"
    
2. The fusion of originally different inflected forms (resulting in a reduction in the use of inflections)
   "Linguistic syncretism is common in the evolution of many languages"

Derived forms: syncretisms

Type of: fusion, unification, union

Encyclopedia: Syncretism