diabolist dia·bo·list UK/dɑːɪˈæbəˌlɪst/ US/dɑɪˈæb əˌlɪst/ uncommon noun 1. an adherent of Satan or Satanism SynonymsSatanist Related words Broader terms disciple WordNet 2.1 (Princeton University). Wiktionary (CC BY-SA). CMU Pronouncing Dictionary. WordNet 2.1 Copyright Princeton University. All rights reserved.