“ecumenic, œcumenic, a.†listed in the Oxford English Dictionary, second edition (1989)
Full definition of œcumenic
Adjective
œcumenic
1835, Isaac Taylor, Spiritual despotism, second edition, chapter VI, page 263 (Holdsworth and Ball)... that great economy of provincial government and of œcumenic relationship ...
1905, Emil Reich, Select Documents Illustrating Mediaeval and Modern History, page 130The first œcumenic council accordingly met at Nicæa, the Emperor’s summer dwelling-place in Bithynia.
1992, Jules Michelet and G. H. Smith, History of France from the earliest period to the present time, page 106 (D. Appleton & Co.)If ever general council was œcumenic, it was this of Constance.