Acephalite

Borrowed from Late Latin acephalus +‎ -ite, from Ancient Greek ἀκέφαλος (aképhalos, “headless”), apparently referring to the movement’s refusal to accept the decisions of church councils.

Acephalite (plural Acephalites)

1. (historical, uncommon) A radical Monophysite in the era after the Council of Chalcedon (451 CE).
   • 1993, John C. Cavadini, The Last Christology of the West: Adoptionism in Spain and Gaul, 785-820, →ISBN, page 43:

     […] nor does he charge Beatus or Heterius (that wild ass) with being a Eutychian, or a follower of Eutyches, or acephalite, or any other term recalling the monophysitism of the fifth century or its descendants.

   • 2012, Jamie Wood, The Politics of Identity in Visigothic Spain: Religion and Power in the Histories of Isidore of Seville, →ISBN, page 212:

     The Greater Chronicle […] makes it clear that the roots of the Acefali lay in their failure to accept the Three Chapters of Chalcedon […] the Lesser Chronicle, 39, states simply that ‘The heresy of the Acephalites arose’ (my translation).

   • 2016, Riemer Faber, transl., Synopsis Purioris Theologiae, →ISBN, page 97:

     Eutyches, who taught the opposite: that just there is one person so the natures are one in Christ, by confusing and intermingling the two natures. So too for that whole breed of Eutyches, the Monophysites, Monothelites, and Acephalites.