1650s, from perfection + -ist. Originally theological, "one who believes moral perfection may be attained in earthly existence, one who believes a sinless life is obtainable." The belief has prevailed from time to time in some Catholic communities, Arminian Methodists, the Society of Friends, etc. The sense of "one satisfied only with the highest standards" is from 1934. Related: Perfectionism.
1705, in reference to various popes who took the name Clement (see clement (adj.)). Saint Clement was a 1c. bishop of Rome. Clement VII was the first of the antipopes of Avignon. Especially in reference to the edition of the Vulgate issued due to Pope Clement VIII in 1592, which was the official Latin Bible text of the Catholic Church until late 20c.
as a noun, in the broadest sense, "member or adherent of a Christian body descended from the Reformation of the 16c. and repudiating papal authority," 1539, from German or French protestant, from Latin protestantem (nominative protestans), present participle of protestari (see protest (n.)).
Originally used of German princes and free cities who declared their dissent from ("protested") the decision of the Diet of Speyer (1529), which reversed the liberal terms allowed Lutherans in 1526.
When forced to make their choice between obedience to God and obedience to the Emperor, they were compelled to choose the former. [Thomas M. Lindsay, "A History of the Reformation," New York, 1910]
The word was taken up by the Lutherans in Germany (Swiss and French preferred Reformed). It became the general word for "adherents of the Reformation in Germany," then "member of any Western church outside the Roman (or Greek) communion;" a sense attested in English by 1553.
In the 17c., 'protestant' was primarily opposed to 'papist,' and thus accepted by English Churchmen generally; in more recent times, being generally opposed to 'Roman Catholic,' or ... to 'Catholic,' ... it is viewed with disfavour by those who lay stress on the claim of the Anglican Church to be equally Catholic with the Roman. [OED]
Often contemptuous shortened form Prot is from 1725, in Irish English. Related: Protestancy. Protestant (work) ethic (1926) is taken from Max Weber's work "Die protestantische Ethik und der 'Geist' des Kapitalismus" (1904). Protestant Reformation attested by 1680s.
"history of the lives, sufferings, and deaths of Christian martyrs," 1590s, a native formation from martyr (n.) + -ology, or else from Church Latin martyrologium, from Ecclesiastical Greek martyrologicon. Especially, in the Catholic Church, "a list or calendar of martyrs, arranged according to their anniversaries." Middle English had martiloge "the register of martyred saints" (late 14c.), from Medieval Latin martilogium. Related: Martyrological.
"companionship, fellowship, association with others," c. 1600, from French sodalité or directly from Latin sodalitatem (nominative sodalitas) "companionship, a brotherhood, association, fellowship," from sodalis "companion," perhaps literally "one's own, relative," related to suescere "to accustom," from PIE *swedh-, extended form of root *s(w)e-, pronoun of the third person and reflexive (see idiom). Especially of religious guilds in the Catholic Church.
1530s, "to make very happy," from French béatifer, from Late Latin beatificare "make happy, make blessed," from Latin beatus "supremely happy, blessed" (past participle of beare "make happy, bless;" see Beatrice) + -ficare, combining form of facere "to make" (from PIE root *dhe- "to set, put"). The Roman Catholic Church sense of "to pronounce as being in heavenly bliss" (1620s) is the first step toward canonization. Related: Beatified; beatifying.