Definition of diaboleptic in US English:

diaboleptic

noun

rare
  • A person (supposedly) possessed by a devil or demon; a person suffering from diabolepsy.

Origin

Late 19th century; earliest use found in Henry Maudsley (1835–1918), medical psychologist. From Hellenistic Greek διάβολος devil + -leptic.

Pronunciation

diaboleptic

/ˌdʌɪabəˈlɛptɪk/