adj. & n.
adj. 1 fiercely energetic or frenzied. 2 a supposedly possessed by an evil spirit. b of or concerning such possession. 3 of or like demons.
n. a person possessed by an evil spirit. demoniacal adj. demoniacally adv.
[ ME f. OF demoniaque f. eccl.L daemoniacus f. daemonium f. Gk daimonion dimin. of daimon: see DEMON) ]