Of or relating to adiaphora or adiaphorists; = adiaphorist.
Adiaphoristic controversy: the disagreement in the Lutheran Church in Germany arising from the Augsburg Interim of 1548 which demanded a return to certain Catholic ceremonies. These were held to be adiaphora by Philipp Melanchthon and his followers, which led to bitter opposition from the orthodox Lutherans..
Origin
Mid 18th century; earliest use found in Archibald Maclaine (1722–1804), Presbyterian minister and historian. From post-classical Latin adiaphoristicus from adiaphorista + -icus. Compare German adiaphoristisch. Compare earlier adiaphorist.