"customs," 1907 (W.G. Sumner, "Folkways"), from Latin mores "customs, manners, morals" (see moral (adj.)).
"behavior, customs, or habits of a people," by 1922, from French moeurs, from Latin mores "customs, manners, morals" (see moral (adj.)).
mid-14c., "associated with or characterized by right behavior," also "associated with or concerning conduct or moral principles" (good or bad), from Old French moral (14c.) and directly from Latin moralis "proper behavior of a person in society," literally "pertaining to manners," coined by Cicero ("De Fato," II.i) to translate Greek ethikos (see ethics) from Latin mos (genitive moris) "one's disposition," in plural, "mores, customs, manners, morals," a word of uncertain origin. Perhaps sharing a PIE root with English mood (n.1).
From late 14c. as "of or pertaining to rules of right conduct" (opposed to non-moral, amoral) and "morally good, in accordance with rules of right conduct" (opposed to immoral). Of persons, "habitually conforming to moral rules," 1630s. From 1680s with reference to rights, duties, etc., "founded on morality" (opposed to legal).
Applied to indirect effect in moral support (1823), moral victory (1888), where the notion is "pertaining to or affecting the character or conduct" (as distinguished from the intellectual or physical nature), a sense attested from 1590s; in this sense, compare morale. Related: Morally.
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]