"to strike sharply," 1719, probably of imitative origin. The noun is from 1737. The word in out of whack (1885) is perhaps the slang meaning "share, just portion" (1785), which may be from the notion of the blow that divides, or the rap of the auctioneer's hammer. To have (or take) a whack at something "make an attempt" is by 1820 (with have), 1845 (with take). Wack or whack "crazy person," 1938, is probably a back-formation from wacky, which probably comes from the blow-on-the-head verb. Related: Whacked; whacking. Whacked out is from 1969.
Wack, whack in the slang sense of "unappealing; crazy," hence "worthless, stupid" is by 1986, apparently popularized by an anti-drug slogan crack is wack.
1857, "mathematical condition of being at right angles, state or fact of being normal in geometry," from normal + -cy. The word has been associated since 1920 with U.S. president Warren G. Harding (who campaigned that year under the slogan "Return to Normalcy," meaning pre-World War I conditions). Previously normalcy was used mostly in the mathematical sense and the word preferred by purists for "a normal situation" is normality. Harding's use of it was derided during his administration as an example of his much-belittled incompetence with the language (Democratic politician William G. McAdoo Jr. called Harding’s speeches "an army of pompous phrases moving across the landscape in search of an idea").
America’s present need is not heroics, but healing; not nostrums, but normalcy; not revolution, but restoration; not agitation, but adjustment; not surgery, but serenity; not the dramatic, but the dispassionate; not experiment, but equipoise; not submergence in internationality, but sustainment in triumphant nationality. [Harding, "Readjustment" speech, May 24, 1920]
Old English bannan "to summon, command, proclaim," from Proto-Germanic *bannan "to speak publicly" (used in reference to various sorts of proclamations), "command; summon; outlaw, forbid" (source also of Old Frisian bonna "to order, command, proclaim," Old High German bannan "to command or forbid under threat of punishment," German bannen "banish, expel, curse"), apparently a Germanic specialization from a suffixed form of PIE root *bha- (2) "to speak, tell, say" (source also of Old Irish bann "law," Armenian ban "word").
From mid-12c. as "to curse, condemn, pronounce a curse upon;" from late 14c. as "to prohibit;" these senses likely are via the Old Norse cognate banna "to curse, prohibit," and probably in part from Old French banir "to summon, banish" (see banish), a borrowing from Germanic. The sense evolution in Germanic was from "speak" to "proclaim a threat" to (in Norse, German, etc.) "curse, anathematize."
The Germanic root, borrowed in Latin and French, has been productive: banal, bandit, contraband, etc. Related: Banned; banning. Banned in Boston dates from 1920s, in allusion to the excessive zeal and power of that city's Watch and Ward Society. Ban the bomb as a slogan of the nuclear disarmament movement is from 1955.
"all right, correct," 1839, only survivor of a slang fad in Boston and New York c. 1838-9 for abbreviations of common phrases with deliberate, jocular misspellings (such as K.G. for "no go," as if spelled "know go;" N.C. for "'nuff ced;" K.Y. for "know yuse"). In the case of O.K., the abbreviation is of "oll korrect."
Probably further popularized by use as an election slogan by the O.K. Club, New York boosters of Democratic president Martin Van Buren's 1840 re-election bid, in allusion to his nickname Old Kinderhook, from his birth in the N.Y. village of Kinderhook. Van Buren lost, the word stuck, in part because it filled a need for a quick way to write an approval on a document, bill, etc.
Spelled out as okeh, 1919, by Woodrow Wilson, on assumption that it represented Choctaw okeh "it is so" (a theory which lacks historical documentation); this spelling was ousted quickly by okay after the appearance of that form in 1929. Greek immigrants to America who returned home early 20c. having picked up U.S. speech mannerisms were known in Greece as okay-boys, among other things.
The noun is first attested 1841, "endorsement, approval, authorization" (especially as indicated by the letters O.K.); the verb, "to approve, agree to, sanction," is by 1888. Okey-doke is student slang first attested 1932.
early 14c., savete, "freedom or immunity from harm or danger; an unharmed or uninjured state or condition," from Old French sauvete, salvete "safety, safeguard; salvation; security, surety," earlier salvetet (11c., Modern French sauveté), from Medieval Latin salvitatem (nominative salvitas) "safety," from Latin salvus "uninjured, in good health, safe" (from PIE root *sol- "whole, well-kept"). From late 14c. as "means or instrument of safety, a safeguard."
The meaning "trigger-lock on a gun" is attested by 1881, perhaps short for safety-lock (1877), etc. As a North American football position, by 1931; as a type of score against one's own team, 1881.
Safety-valve, which diminishes the risk of explosion, is from 1797; figurative sense recorded from 1818. Safety-net in literal sense (in machinery) is by 1916, later of aerial circus performances (1920s); figurative use is by 1950. Safety-bicycle as a name for the modern type, with low, equal-sized wheels and a driving mechanism, is by 1866. Safety-razor is by 1877. A safety-belt (1840) was at first for window washers and firefighters; it was used of restraining straps for airplane pilots by 1911, extended to automobiles by 1948. Safety first as an accident-prevention slogan first recorded 1873.
Safety first, and saving of fuel second, should be the rule in steam engineering. [Scientific American, June 15, 1861]