IPA: //daɪˈæbəlɪst//
KK: /daɪˈæbəlɪst/
A person who follows or believes in Satan or Satanism.
The diabolist held secret meetings to discuss their beliefs.
Diabolist → It is formed from "diabolus" (from Greek "diabolos", meaning slanderer or accuser) and the suffix "-ist" (meaning one who practices or is concerned with). A diabolist is someone who practices or is concerned with the devil or evil, often in a supernatural context.
Think of a 'slanderer' ('diabolus') who is associated with evil, and remember that a diabolist is someone who engages with or practices the dark arts.