reunionist

re·un·ion·ist

 (rē-yo͞on′yə-nĭst)
n.
One who advocates reunion, as of divided parties or sects, especially the reunion of the Catholic and Protestant branches of Christianity.

re·un′ion·ism n.
re·un′ion·is′tic adj.
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.

reunionist

(riːˈjuːnjənɪst)
n
(Ecclesiastical Terms) a person who desires or works for reunion between the Roman Catholic Church and the Church of England
reˈunionism n
reˌunionˈistic adj
Collins English Dictionary – Complete and Unabridged, 12th Edition 2014 © HarperCollins Publishers 1991, 1994, 1998, 2000, 2003, 2006, 2007, 2009, 2011, 2014
References in periodicals archive ?
(61) Manfred Fleischer, "Lutheran and Catholic Reunionists in the Age of Bismarck," Church History 38, no.
Still, he said most of his fellow reunionists looked older and balder than he did, so that cheered him up.