c. 1200, "the sufferings of Christ on the Cross; the death of Christ," from Old French passion "Christ's passion, physical suffering" (10c.), from Late Latin passionem (nominative passio) "suffering, enduring," from past-participle stem of Latin pati "to endure, undergo, experience," a word of uncertain origin. The notion is "that which must be endured."

The sense was extended to the sufferings of martyrs, and suffering and pain generally, by early 13c. It replaced Old English þolung (used in glosses to render Latin passio), literally "suffering," from þolian (v.) "to endure." In Middle English also sometimes "the state of being affected or acted upon by something external" (late 14c., compare passive).

In Middle English also "an ailment, disease, affliction;" also "an emotion, desire, inclination, feeling; desire to sin considered as an affliction" (mid-13c.). The specific meaning "intense or vehement emotion or desire" is attested from late 14c., from Late Latin use of passio to render Greek pathos "suffering," also "feeling, emotion." The specific sense of "sexual love" is attested by 1580s, but the word has been used of any lasting, controlling emotion (zeal; grief, sorrow; rage, anger; hope, joy). The meaning "strong liking, enthusiasm, predilection" is from 1630s; that of "object of great admiration or desire" is by 1732.

As compared with affection, the distinctive mark of passion is that it masters the mind, so that the person becomes seemingly its subject or its passive instrument, while an affection, though moving, affecting, or influencing one, still leaves him his self-control. The secondary meanings of the two words keep this difference. [Century Dictionary]

A passion-play (1843, in a German context) represents the scenes in the Passion of Christ. The passion-flower was so called from the 1630s.

The name passionflower — flos passionis — arose from the supposed resemblance of the corona to the crown of thorns, and of the other parts of the flower to the nails, or wounds, while the five sepals and five petals were taken to symbolize the ten apostles — Peter ... and Judas ... being left out of the reckoning. [Encyclopaedia Britannica, 1885]

1590s, "pertaining to the island of Lesbos," from Latin Lesbius, from Greek lesbios "of Lesbos," Greek island in northeastern Aegean Sea (the name originally may have meant "wooded"), home of Sappho, great lyric poet whose erotic and romantic verse embraced women as well as men, hence meaning "relating to homosexual relations between women, characterized by erotic interest in other women" (in continuous use from 1890; the noun lesbianism from this sense is attested from 1870) and the noun, which is first recorded 1925.

Sappho's particular association with erotic love between women (with or without concurrent relations with men) dates to at least 1732 in writing in English, though the continuous use of lesbian and the modern words formed from it are from late 19c. The use of lesbian as a noun and an adjective in this sense seems to follow the same pattern.  

In another Place the same commentator conjectures, that Myra is a Corruption of Myrrhina а famous Courtesan of Athens, who first practis'd and taught in that City Sappho's Manner and the Lesbian Gambols. ["Peregrine O Donald" (William King), "The Toast," 1732]

Before this, the principal figurative use of Lesbian was lesbian rule (c. 1600 and especially common in 17c.) a mason's rule of lead, of a type used in ancient times on Lesbos, which could be bent to fit the curves of a molding; hence, figuratively, "pliant morality or judgment."

And this is the nature of the equitable, a correction of law where it is defective owing to its universality. ... For when the thing is indefinite the rule also is indefinite, like the leaden rule used in making the Lesbian moulding; the rule adapts itself to the shape of the stone and is not rigid, and so too the decree is adapted to the facts. [Aristotle, "Nicomachean Ethics"]

It also was used in English from 1775 in reference to wines from Lesbos. Though the specific "pertaining to female homosexuality" is recent, Lesbian had long before that a suggestion of "amatory, erotic," "From the reputed character of the inhabitants and the tone of their poetry" [Century Dictionary]. The island's erotic reputation was ancient; Greek had a verb lesbiazein "to imitate the Lesbians," which implied "sexual initiative and shamelessness" among women (especially fellatio), but not necessarily female homosexuality, and they did not differentiate such things the way we have.

late Old English wyrre, werre "large-scale military conflict," from Old North French werre "war" (Old French guerre "difficulty, dispute; hostility; fight, combat, war;" Modern French guerre), from Frankish *werra, from Proto-Germanic *werz-a- (source also of Old Saxon werran, Old High German werran, German verwirren "to confuse, perplex"), from PIE *wers- (1) "to confuse, mix up". Cognates suggest the original sense was "to bring into confusion."

Spanish, Portuguese, and Italian guerra also are from Germanic; Romanic peoples turned to Germanic for a "war" word possibly to avoid Latin bellum (see bellicose) because its form tended to merge with bello- "beautiful." There was no common Germanic word for "war" at the dawn of historical times. Old English had many poetic words for "war" (wig, guð, heaðo, hild, all common in personal names), but the usual one to translate Latin bellum was gewin "struggle, strife" (related to win (v.)).

First record of war-time is late 14c. Warpath (1775) originally is in reference to North American Indians, as are war-whoop (1761), war-paint (1826), and war-dance (1757). War crime is attested from 1906 (in Oppenheim's "International Law"). War chest is attested from 1901; now usually figurative. War games translates German Kriegspiel (see kriegspiel).

The causes of war are always falsely represented ; its honour is dishonest and its glory meretricious, but the challenge to spiritual endurance, the intense sharpening of all the senses, the vitalising consciousness of common peril for a common end, remain to allure those boys and girls who have just reached the age when love and friendship and adventure call more persistently than at any later time. The glamour may be the mere delirium of fever, which as soon as war is over dies out and shows itself for the will-o'-the-wisp that it is, but while it lasts no emotion known to man seems as yet to have quite the compelling power of this enlarged vitality. [Vera Brittain, "Testament of Youth"]

The world will never have lasting peace so long as men reserve for war the finest human qualities. [John Foster Dulles, Speech on the Marshall Plan, 1948]

Middle English setten, from Old English settan (transitive) "cause to sit; make or cause to rest as on a seat; cause to be put, placed, or seated;" also "put in a definite place," also "arrange, fix adjust; fix or appoint (a time) for some affair or transaction," and "cause (thoughts, affections) to dwell on."

This is from Proto-Germanic *(bi)satejanan "to cause to sit, set" (source also of Old Norse setja, Swedish sätta, Old Saxon settian, Old Frisian setta, Dutch zetten, German setzen, Gothic satjan), causative form of PIE *sod-, a variant of the root *sed- (1) "to sit." Also see set (n.2). It has been confused with sit (v.) at least since early 14c. 

The intransitive sense of "be seated" is from c. 1200; that of "sink down, descend, decline toward and pass below the horizon" (of the sun, moon, or stars) is by mid-13c., perhaps from similar use of the cognates in Scandinavian languages; figurative use of this is from c. 1600.

Many uses are highly idiomatic, the verb, like put, its nearest equivalent, and do, make, get, etc., having become of almost universal application, and taking its distinctive color from the context. [Century Dictionary]

The sense of "make or cause to do, act, or be; start, bring (something) to a certain state" (on fire, in order, etc.) and that of "mount a gemstone" are attested by mid-13c. That of "determine upon, resolve" is from c. 1300; hence be set against "resisting" (mid-14c.).

The sense of "make a table ready for a meal" is from late 14c.; that of "regulate or adjust by a standard" (of a clock, etc.) is from late 14c. In printing, "to place (types) in the proper order for reading; put into type," 1520s. From c. 1500 as "put words to music." From 1570s as "put (a broken or dislocated bone) in position." In cookery, plastering, etc., "become firm or solid in consistency" by 1736.

To set (one's) heart on (something) is from c. 1300 as "love, be devoted to;" c. 1400 as "have a desire for." To set (one's) mind is from mid-15c.; transitive set (one's mind) to "determine to accomplish" is from late 15c.  To set (something) on "incite to attack" (c. 1300) originally was in reference to hounds and game. To set an example is mid-14c. (set (v.) in the sense of "present" is from late Old English). The notion of "fix the value of" is behind old phrases such as set at naught "regard as nothing."

To set out is from c. 1300 as "display (for sale);" to set up shop "commence doing business" is from c. 1400.

parting salutation, 1860, of unknown origin, perhaps from a German idiom (compare German parting salutation adieu so lange, the full sense of which probably is something like "farewell, whilst (we're apart)"); or perhaps from or influenced by Hebrew shalom (via Yiddish sholom). Some have noted a similarity to Scandinavian leave-taking phrases, such as Norwegian Adjø så lenge, Farvel så lenge, Mor'n så lenge, literally "bye so long, farewell so long, morning so long;" and Swedish Hej så länge "good-bye for now," with så länge "for now" attested since 1850 according to Swedish sources, with sense as in the German phrase. Etymology sources seem to lean toward the German origin. The adverbial so long "for such a long time" is from late Old English (swa lange); see so.

Earlier guesses that it was a sailors' corruption of a South Pacific form of Arabic salaam are not now convincing. "Dictionary of American Slang" also adds to the list of candidates Irish slán "safe," said to be used as a salutation in parting.

The phrase seems to have turned up simultaneously in America, Britain, and perhaps Canada, originally among lower classes. The first attested use is in title and text of the last poem in Whitman's "Leaves of Grass" in the 1860 edition.

An unknown sphere, more real than I dream'd, more direct, darts awakening rays about me — So long!

Remember my words — I may again return,

I love you — I depart from materials;

I am as one disembodied, triumphant, dead.

Whitman's friend and fan William Sloane Kennedy wrote in 1923:

The salutation of parting — 'So long!' — was, I believe, until recent years, unintelligible to the majority of persons in America, especially in the interior, and to members of the middle and professional classes. I had never heard of it until I read it in Leaves of Grass, but since then have quite often heard it used by the laboring class and other classes in New England cities. Walt wrote to me, defining 'so long' thus: "A salutation of departure, greatly used among sailors, sports, & prostitutes — the sense of it is 'Till we meet again,' — conveying an inference that somehow they will doubtless so meet, sooner or later." ... It is evidently about equivalent to our 'See you later.' The phrase is reported as used by farm laborers near Banff, Scotland. In Canada it is frequently heard; 'and its use is not entirely confined to the vulgar.' It is in common use among the working classes of Liverpool and among sailors at Newcastle-upon-Tyne, and in Dorsetshire. ... The expression is now (1923) often used by the literary and artistic classes.

"of the color of the clear sky," c. 1300, bleu, blwe, etc., "sky-colored," also "livid, lead-colored," from Old French blo, bleu "pale, pallid, wan, light-colored; blond; discolored; blue, blue-gray," from Frankish *blao or some other Germanic source, from Proto-Germanic *blæwaz (source also of Old English blaw, Old Saxon and Old High German blao, Danish blaa, Swedish blå, Old Frisian blau, Middle Dutch bla, Dutch blauw, German blau "blue").

This is from PIE *bhle-was "light-colored, blue, blond, yellow," from root *bhel- (1) "to shine, flash, burn," also "shining white" and forming words for bright colors. The same PIE root yielded Latin flavus "yellow," Old Spanish blavo "yellowish-gray," Greek phalos "white," Welsh blawr "gray," showing the slipperiness of definition in Indo-European color-words. Many Indo-European languages seem to have had a word to describe the color of the sea, encompassing blue and green and gray; such as Irish glass (from PIE root *ghel- (2) "to shine,"); Old English hæwen "blue, gray," related to har (see hoar); Serbo-Croatian sinji "gray-blue, sea-green;" Lithuanian šyvas, Russian sivyj "gray."

The exact color to which the Gmc. term applies varies in the older dialects; M.H.G. bla is also 'yellow,' whereas the Scandinavian words may refer esp. to a deep, swarthy black, e.g. O.N. blamaðr, N.Icel. blamaður 'Negro' [Buck] 

The present spelling in English is since 16c., common from c. 1700. The sense "lead-colored, blackish-blue, darkened as if by bruising" is perhaps by way of the Old Norse cognate bla "livid, lead-colored." It is the meaning in black and blue, and blue in the face "livid with effort" (1864, earlier black and blue in the face, 1829).

The color of constancy since Chaucer at least, but apparently for no deeper reason than the rhyme in true blue (c. 1500). The figurative meaning "sad, sorrowful, afflicted with low spirits" is from c. 1400, perhaps from the "livid" sense and implying a bruised heart or feelings. Of women, "learned, pedantic," by 1788 (see bluestocking). In some phrases, such as blue murder, it appears to be merely intensive.

Few words enter more largely into the composition of slang, and colloquialisms bordering on slang, than does the word BLUE. Expressive alike of the utmost contempt, as of all that men hold dearest and love best, its manifold combinations, in ever varying shades of meaning, greet the philologist at every turn. [John S. Farmer, "Slang and Its Analogues Past and Present," 1890, p.252] 

Blue pencil as an editor's characteristic tool to mark corrections in copy is from 1885; also as a verb from 1885. The fabulous story of Blue-beard, who kept his murdered wives in a locked room, is in English from 1798. For blue ribbon see cordon bleu under cordon. Blue whale is attested from 1851, so called for its color. Blue cheese is from 1862. Blue water "the open ocean" is from 1822. Blue streak, of something resembling a bolt of lightning (for quickness, intensity, etc.) is from 1830, Kentucky slang. Delaware has been the Blue Hen State at least since 1830, supposedly from a nickname of its regiments in the Revolutionary War.