The term "Demonship" is relatively uncommon and may not have many synonyms. However, some possible alternatives for this word include "demonology," "demonic worship," "devil worship," "demon worship," "infernal devotion," "hellish allegiance," and "Satanic devotion." Each of these words can be used to describe the act of worshipping or giving devotion to demons or other malevolent supernatural beings. While these words may have slightly different connotations or implications, they all relate to the same general idea of engaging in practices or beliefs that revolve around the darker elements of spiritual or supernatural forces.