c. 1400, "avowal, pledge, solemn declaration," from Old French protest, from protester, from Latin protestari "declare publicly, testify, protest," from pro- "forth, before" (from PIE root *per- (1) "forward," hence "in front of, before") + testari "testify," from testis "witness" (see testament).
Meaning "statement of disapproval" is recorded by 1751. By late 19c. this was mostly restricted to "a solemn or formal declaration against some act or course of action."
The adjectival sense of "expressing of dissent from, or rejection of, prevailing social, political, or cultural mores" is by 1942, in reference to U.S. civil rights movement (in protest march); protest rally from 1960. Protest vote, "vote cast to demonstrate dissatisfaction with the choice of candidates or the current system," is by 1905 (in reference to Socialist Party candidates).
Because they now fully understood the power of the picket line, they were ready and anxious to march on Washington when A. Philip Randolph, president of the Brotherhood of Sleeping Car Porters, advanced the idea in January 1941 of organizing a Negro protest march on Washington, because Government officials from the President down to minor bureau chiefs, had persistently evaded the issue of combating discrimination in defense industries as well as the Government itself. As the time for the event drew nearer some of the heads of the Government became alarmed; Randolph reported that a ranking New Dealer had told him many Government officials were asking, "What will they think in Berlin?" [Statement of Edgar G. Brown, Revenue Revision of 1942 hearings, 77th Congress, 2nd session]
mid-15c., protesten, "to declare or state formally or solemnly, bear witness or testimony to," from Old French protester and directly from Latin protestari "declare publicly, testify, protest" (see protest (n.)). Original sense preserved in to protest one's innocence. The meaning "make a solemn or formal declaration (often in writing) in condemnation of an act or measure, proposed or accomplished," is from c. 1600. The word's association with marches and rallies arose in 20c. Related: Protested; protesting.
also protestor, 1540s, protestour, "one who makes solemn affirmation or declaration;" agent noun from protest (v.). From 1960 as "demonstrator against or public opponent of the established order."
mid-14c., protestacioun, "affirmation;" late 14c., "avowal, a solemn or formal declaration or assertion," from Old French protestacion "protest, protestation" (13c.) and directly from Late Latin protestationem (nominative protestatio) "a declaration, protestation," noun of action from past-participle stem of Latin protestari "declare publicly, testify, protest" (see protest (n.)). By 1640s as "solemn or formal declaration of dissent."
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.
1580s, "action of remonstrating in a friendly manner;" 1590s, "argumentative protest," from Latin expostulationem (nominative expostulatio) "a pressing demand, complaint," noun of action from past-participle stem of expostulare "demand urgently," from ex "from" (see ex-) + postulare "to demand" (see postulate (v.)).