pris·cil·lian·ist I. \-yənə̇st\noun (-s) Usage: usually capitalized Etymology:Priscillian died A.D.385 + English -ist 1.: an adherent of Priscillianism or a follower of Priscillian 2.[Priscilla, prophetess associated with the founder of Montanism + English -ist]: montanist II. adjective Usage: usually capitalized : of or relating to the Priscillianists or their beliefs