Don·a·tist (d?n??-t?st, d??n?-)n. A member of a rigoristic, schismatic Christian sect, strongly opposed by Saint Augustine, that arose in North Africa in the fourth century ad and believed in sanctity as requisite for church membership and administration of all sacraments.[Medieval Latin Donatista, after Donatus, fourth-century ad ecclesiastic and rival claimant of the bishopric of Carthage.]Don?a·tism n.American Heritage® Dictionary of the English Language, Fifth Edition. Copyright © 2016 by Houghton Mifflin Harcourt Publishing Company. Published by Houghton Mifflin Harcourt Publishing Company. All rights reserved.Donatisma heretical cult in N. Africa during the 4th through 7th centuries that emphasized high morality and rebaptism as necessary for church mem-bership and considered invalid a sacrament celebrated by an immoral priest. ? Donatist, n. ? Donatistic, adj.See also: Heresy-Ologies & -Isms. Copyright 2008 The Gale Group, Inc. All rights reserved.