Source : Webster's Revised Unabridged Dictionary (1913)

Energumen \En`er*gu"men\, n. [L. energumenos, fr. Gr. ?
   possessed by an evil spirit, from ?: cf. F. ['e]nergum[`e]ne.
   See {Energetic}.] (Eccl. Antiq.)
   One possessed by an evil spirit; a demoniac.