Quiz: Remember the definition of mal de mer?
mid-14c., "of the doctrines of the ancient Church," literally "universally accepted," from French catholique, from Church Latin catholicus "universal, general," from Greek katholikos, from phrase kath' holou "on the whole, in general," from kata "about" + genitive of holos "whole" (see safe (adj.)). Applied to the Church in Rome c.1554, after the Reformation began. General sense of "of interest to all, universal" is from 1550s.
(from Greek katholikos, "universal"), the characteristic that, according to ecclesiastical writers since the 2nd century, distinguished the Christian Church at large from local communities or from heretical and schismatic sects. A notable exposition of the term as it had developed during the first three centuries of Christianity was given by St. Cyril of Jerusalem in his Catecheses (348): the church is called catholic on the ground of its worldwide extension, its doctrinal completeness, its adaptation to the needs of men of every kind, and its moral and spiritual perfection.