Christadelphian

Coined by English religious leader and founder of the Christadelphian movement John Thomas, from Ancient Greek Χριστός (Khristós, “Christ”) + ἀδελφός (adelphós, “brother”).

Christadelphian (plural Christadelphians)

1. A member of a particular nontrinitarian Christian denomination founded in the mid-19th century.
   • 1925 July – 1926 May, A[rthur] Conan Doyle, “Which Describes an Evening in Strange Company”, in The Land of Mist (eBook no. 0601351h.html), Australia: Project Gutenberg Australia, published April 2019:

     When Malone next looked round he was gone. "He is one of these Second-coming fanatics," he whispered to Enid. There are a lot of them—Christadelphians, Russellites, Bible Students and what-not.

Christadelphian

1. Pertaining to the Christadelphians.