Any one of a group of moderate Lutherans led by Phillipp Melanchthon, who advocated certain issues and ceremonies to be considered as adiaphora and not central to the Protestant faith.
2A person who holds that differences of religious belief are unimportant; one who allows latitude or flexibility with regard to religious matters; an indifferentist, a latitudinarian.
Of, relating to, or of the nature of an adiaphorist or adiaphorists; that allows latitude in religious matters.
Mid 16th century; earliest use found in John Daus (c1516–1602), schoolmaster and translator. From post-classical Latin adiaphorista from adiaphorus indifferent + -ista.