Bible Encyclopedias
Encyclical

1911 Encyclopedia Britannica

(from Late Lat. encyclicus, for encyclius= Gr. yKUKXcos, from iv and KuKXos, " a circle"), an ecclesiastical epistle intended for general circulation, now almost exclusively used of such letters issued by the pope. The forms encyclica and encyclic are sometimes, but more rarely, used. The old adjectival use of the word in the sense of "general" (encircling) is now obsolete, though it survives in the term "encyclopaedia."

Bibliography Information
Chisholm, Hugh, General Editor. Entry for 'Encyclical'. 1911 Encyclopedia Britanica. https://www.studylight.org/​encyclopedias/​eng/​bri/​e/encyclical.html. 1910.