Online Etymology Dictionary

blotting (n.): mid-15c., verbal noun from blot (v.). Blotting paper is recorded from 1510s.
blotto (adj.): "drunk," c.1905, from some signification of blot (v.) in its "soak up liquid" meaning.
blouse (n.): 1828 (from 1822 as a French word in English), from French blouse, "workman's or peasant's smock" (1788), origin unknown. Perhaps akin to Provençal (lano) blouso "short (wool)" [Gamillscheg]. Another suggestion [Klein] is that it is from Medieval Latin pelusia, from Pelusium, a city in Upper Egypt, supposedly a clothing manufacturing center in the Middle Ages.
In Paris, a very slovenly, loose, drawn frock, with most capacious sleeves, had been introduced called a blouse. Some of our priestesses of the toilet seemed emulous of copying this deshabille, with some slight alterations, but we never wish to see it on the symmetrical form of a British lady. ["Summary of Fashion for 1822," in "Museum of Foreign Literature and Science," Jan.-June 1823]
bloviate (v.): 1857, American English, a Midwestern word for "to talk aimlessly and boastingly; to indulge in 'high falutin'," according to Farmer (1890), who seems to have been the only British lexicographer to notice it. He says it was based on blow (v.) on the model of deviate, etc.

It seems to have been felt as outdated slang already by late 19c. ("It was a leasure for him to hear the Doctor talk, or, as it was inelegantly expressed in the phrase of the period, 'bloviate' ...." ["Overland Monthly," San Francisco, 1872, describing a scene from 1860]), but it enjoyed a revival early 1920s during the presidency of Warren G. Harding, who wrote a notoriously ornate and incomprehensible prose (e.e. cummings eulogized him as "The only man, woman or child who wrote a simple declarative sentence with seven grammatical errors") at which time the word took on its connection with political speech; it faded again thereafter, but, with its derivative, bloviation, it enjoyed a revival in the 2000 U.S. election season that continued through the era of blogging.
bloviation (n.): "pompous oratory," 1857; noun of action; see bloviate.
blow (v.1): "move air," Old English blawan "blow, breathe, make an air current; kindle; inflate; sound a wind instrument" (class VII strong verb; past tense bleow, past participle blawen), from Proto-Germanic *blæ-anan (cf. Old High German blaen, German blähen), from PIE *bhle- "to swell, blow up" (cf. Latin flare "to blow"), possibly identical with *bhel- (2) "to blow, swell" (see bole).

Meaning "to squander" (of money) is from 1874. Sense of "depart suddenly" is from 1902. Slang "do fellatio on" sense is from 1933, as blow (someone) off, originally among prostitutes (cf. blow job). This usage probably is not connected to the colloquial imprecation (1781, associated with sailors, e.g. Popeye's "well, blow me down!"), which has past participle blowed. Meaning "to spend (money) foolishly and all at once" is 1890s; that of "bungle an opportunity" is from 1943. To blow over "pass" is from 1610s, originally of storms. To blow (someone's) mind was in use by 1967; there is a song title "Blow Your Mind" released in a 1965 Mirawood recording by a group called The Gas Company.
blow (v.2): "to bloom, blossom" (intransitive), from Old English blowan "to flower, blossom, flourish," from Proto-Germanic *blæ- (cf. Old Saxon bloian, Old Frisian bloia, Middle Dutch and Dutch bloeien, Old High German bluoen, German blühen), from PIE *bhle-, extended form of *bhel- (2) "to blow, inflate, swell" (see bole). This word is the source of the blown in full-blown.
blow (n.1): "hard hit," mid-15c., blowe, from northern and East Midlands dialects, perhaps from Middle Dutch blouwen "to beat," a common Germanic word of unknown origin (cf. German bleuen, Gothic bliggwan "to strike"). Influenced in English by blow (v.1). In reference to descriptions or accounts, blow-by-blow is recorded from 1921, American English, originally of prize-fight broadcasts.
LIKE a hungry kitten loves its saucer of warm milk, so do radio fans joyfully listen to the blow-by-blow broadcast description of a boxing bout. ["The Wireless Age," December 1922]
blow (n.2): "a blowing, a blast," 1650s, from blow (v.1).
blow job (n.): also blowjob, 1961, from blow + job. Exactly which blow is meant is the subject of some debate; the word might have begun as a euphemism for suck (thus from blow (v.1)), or it might refer to the explosive climax of an orgasm (thus blow (v.2)). Unlike much sex slang, its date of origin probably is pretty close to the date it first is attested in print: as recently as the early 1950s, military pilots could innocently talk of their jet planes as blow jobs according to the "Thesaurus of American Slang." Cf. blow (v.1).
blow out (n.): also blowout, 1825, American English colloquial, "outburst, brouhaha" (what, in modern use, would be called a blow up), from blow (v.1) + out. Meaning "abundant feast" is recorded from 1824; that of "flat tire" is from 1908.
blow up (v.): "explode," 1590s, from blow (v.1) + up. As a noun, it is recorded from 1809 in the sense "outburst, quarrel." Meaning "enlargement from a photograph" is attested by 1945.
blow-dry (v.): 1971, of hair; see blow (v.1) + dry (v.). Related: Blow-dried; blow-drying.
blow-fly (n.): 1720, from fly (n.) + blow (v.1) in an obsolete sense "to deposit eggs, to infect with eggs," in reference to to insects, "apparently connected with old notions of natural history" [OED].
blow-gun (n.): type of weapon, 1799, from blow (v.1) + gun (n.).
blow-pipe (n.): type of weapon, 1680s, from blow (v.1) + pipe (n.1).
blowback (n.): also blow-back, 1883, in reference to flames in enclosed spaces (firearms, furnaces, etc.), from blow (v.1) + back (adv.). Sense in reference to convert actions, etc., is from 1978.
blower (n.): early 12c. (originally of horn-blowers), from Old English blawere, agent noun from blow (v.1). Of mechanical devices from 1795.
blowfish (n.): also blow-fish, 1862, American English, from blow (v.1) + fish (n.).
Then he described another odd product of the bay, that was known as the blow-fish, and had the power of inflating himself with air when taken out of the water. ["The Young Nimrods in North America," New York, 1881]
blowhard (n.): also blow-hard, 1840, a sailor's word (from 1790 as a nickname for a sailor), perhaps not originally primarily meaning "braggart;" from blow (v.1) + hard (adv.). An adjective sense of "boastful" appeared c.1855, and may be a separate formation leading to a modified noun use.
blowhole (n.): also blow-hole, 1787, of whales and porpoises, from blow (v.1) + hole.
blown (adj.): early 15c., "inflated," from Old English blawen, past participle of blow (v.1). Figurative sense of "inflated by pride" is from late 15c. Meaning "out of breath" is from 1670s. As a past participle adjective from blow (v.2), it was Old English geblowenne.
blowzy (adj.): c.1770, from obsolete blouze (1570s), "wench, beggar's trull," perhaps originally a cant term, + -y (2).
blub (n.): "fit of weeping," 1894, imitative. As a verb by 1843. Related: Blubbed; blubbing.
blubber (n.): late 14c., blober "a bubble, bubbling water; foaming waves," probably echoic of bubbling water. Original notion of "bubbling, foaming" survives in the figurative verbal meaning "to weep, cry" (c.1400). Meaning "whale fat" first attested 1660s; earlier it was used in reference to jellyfish (c.1600) and of whale oil (mid-15c.). As an adjective from 1660s.
blubber (v.): late 14c., "to seethe, bubble," from blubber (n.). Meaning "to cry, to overflow with weeping" is from c.1400. Related: Blubbered; blubbering.
blubbering: c.1400, present participle adjective from blubber (v.). Originally of fountains, springs, etc.; of weeping, from 1580s. As a verbal noun, from 1570s.
blubbery (adj.): 1791, from blubber (n.) + -y (2).
Bluchers (n.): type of old-style boots, from Prussian Field Marshal Gebhard Leberecht Blücher (1742-1819).
bludge (v.): "shirk responsibility," 1919, Australian and New Zealand slang, earlier "be a prostitute's pimp," from bludger "pimp."
bludgeon (v.): 1802, from earlier noun bludgeon "short club" (1730), of unknown origin. Related: Bludgeoned; bludgeoning.
bludgeon (n.): "short club," 1730, of unknown origin.
bludger (n.): "prostitute's pimp," 1856, short for bludgeoner, agent noun from bludgeon (v.).
blue (1): c.1300, bleu, blwe, etc., from Old French blo "pale, pallid, wan, light-colored; blond; discolored; blue, blue-gray," from Frankish *blao or some other Germanic source, from Proto-Germanic *blæwaz (cf. 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"), from PIE *bhle-was "light-colored, blue, blond, yellow," from PIE root bhel- (1) "to shine, flash" (see bleach (v.)).

The same PIE root yielded Latin flavus "yellow," Old Spanish blavo "yellowish-gray," Greek phalos "white," Welsh blawr "gray," Old Norse bla "livid" (the meaning in black and blue), showing the usual slippery definition of color words in Indo-European The present spelling is since 16c., from French influence (Modern French bleu).
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]

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]
The color of constancy since Chaucer at least, but apparently for no deeper reason than the rhyme in true blue (c.1500). From early times blue was the distinctive color of the dress of servants, which may be the reason police uniforms are blue, a tradition Farmer dates to Elizabethan times. For blue ribbon see cordon bleu under cordon. Blue whale attested from 1851, so called for its color. The flower name blue bell is recorded by 1570s. Blue streak, of something resembling a blt of lightning (for quickness, intensity, etc.) is from 1830, U.S. Western slang.

Many Indo-European languages seem to have had a word to describe the color of the sea, encompasing blue and green and gray; e.g. Irish glass (see Chloe); Old English hæwen "blue, gray," related to har (see hoar); Serbo-Croatian sinji "gray-blue, sea-green;" Lithuanian šyvas, Russian sivyj "gray."
blue (2): "lewd, indecent" recorded from 1840 (in form blueness, in an essay of Carlyle's); the sense connection is unclear, and is opposite to that in blue laws (q.v.). John Mactaggart's "Scottish Gallovidian Encyclopedia" (1824) containing odd words he had learned while growing up in Galloway and elsewhere in Scotland, has an entry for Thread o'Blue, "any little smutty touch in song-singing, chatting, or piece of writing." Farmer ["Slang and Its Analogues Past and Present," 1890] offers the theory that this meaning derives from the blue dress uniforms issued to harlots in houses of correction, but he writes that the earlier slang authority John Camden Hotten "suggests it as coming from the French Bibliothèque Bleu, a series of books of very questionable character," and adds, from Hotten, that, "Books or conversation of an entirely opposite nature are said to be Brown or Quakerish, i.e., serious, grave, decent."
blue (v.): "to make blue," c.1600, from blue (1).
blue blood: 1834, translating Spanish sangre azul, claimed by certain families of Castile as uncontaminated by Moorish or Jewish admixture, probably from the notion of the visible veins of people of fair complexion.
blue chip (adj.): also blue-chip, in reference to the high-value poker counter, from 1904 in the figurative sense of "valuable;" stock exchange sense, in reference to "shares considered a reliable investment," is first recorded 1929; especially of stocks that saw spectacular rises in value in the four years or so before the Wall Street crash of that year.
blue collar (adj.): also blue-collar, 1949, from blue (1) + collar (n.). From the common color of men's work shirts.
blue jeans: from 1843 as a type of fabric; see jean. As short for blue jeans trousers, from 1878.
blue laws: 1781, severe Puritanical code said to have been enacted 18c. in New Haven, Connecticut; of uncertain origin, perhaps from one of the ground senses behind blues, or from notion of coldness. Or perhaps connected to bluestocking in the sense of "puritanically plain or mean" (see bluestocking, which is a different application of the same term; the parliament of 1653 was derisively called the bluestocking parliament). The common explanation that they were written on blue paper is not considered valid; pale blue paper was used for many old U.S. legal documents and there would have been nothing notable about its use in this case.
blue moon (n.): 1821 as a specific term in the sense "very rarely," perhaps suggesting something that, in fact, never happens (cf. at the Greek calends, and the native in the reign of Queen Dick, reported in Grose (1788)); suggested earliest in this couplet from 1528:
Yf they say the mone is blewe,
We must beleve that it is true.
Though this might refer to calendrical calculations by the Church, so that the general sense of the term and the specific one (commonly misinterpreted as "second full moon in a calendar month," but actually a quarterly calculation) are difficult to disentangle. In either case, the sense of blue is obscure. Literal blue moons do sometimes occur under extreme atmospheric conditions.
blueberry (n.): c.1775, from blue (1) + berry.
bluebird (n.): also blue-bird, North American warbler-like bird, 1680s, from blue (1) in reference to its plumage + bird (n.1). Figurative use in bluebird of happiness is from 1909 play romance "l'Oiseau bleu," literally "The Blue Bird," by Belgian dramatist and poet Maurice Maeterlinck (1862-1949).
bluegrass (n.): also blue-grass, music style, 1958, in reference to the Blue Grass Boys, country music band 1940s-'50s, from the "blue" grass (Poa pratensis) characteristic of Kentucky, the grass so called from 1751. Kentucky has been called the Bluegrass State since at least 1872; see blue (n.) + grass.
blueing (n.): "substance which makes (something) blue," 1660s, verbal noun from blue (v.).
blueprint (n.): also blue-print, 1882, from blue (1) + print (n.). The process uses blue on white, or white on blue. Figurative sense of "detailed plan" is attested from 1926. As a verb by 1939.
blues (n.): as a music form featuring flatted thirds and sevenths, possibly c.1895 (though officially 1912, in W.C. Handy's "Memphis Blues"); meaning "depression, low spirits" goes back to 1741, from adjectival blue "low-spirited," late 14c.
bluestocking (n.): also blue-stocking, 1790, derisive word for a woman considered too learned, traces to a London literary salon founded c.1750 by Elizabeth Montagu on the Parisian model, featuring intellectual discussion instead of card games, and in place of ostentatious evening attire, simple dress, including Benjamin Stillingfleet's blue-gray tradesman's hose which he wore in place of gentleman's black silk, hence the term, first applied in derision to the whole set by Admiral Boscawen. None of the ladies wore blue stockings. Borrowed by the neighbors in loan-translations, cf. French bas-bleu, Dutch blauwkous, German Blaustrumpf.
bluesy (adj.): 1946, from blues + -y (2).