Online Etymology Dictionary

barmy (adj.): 1530s, "frothing, covered with barm;" see barm + -y (2). Figurative sense of "excited, flighty, bubbling with excitement" is from c.1600. Meaning "foolish" (1892) is probably an alteration of balmy.
barn (n.): Old English bereærn "barn," literally "barley house," from bere "barley" (see barley) + aern "house," metathesized from *rann, *rasn (cf. Old Norse rann, Gothic razn "house," Old English rest "resting place").
Barley was not always the only crop grown as the data recovered at Bishopstone might suggest but it is always the most commonly represented, followed by wheat and then rye and oats. [C.J. Arnold, "An Archaeology of the Early Anglo-Saxon Kingdoms," 1988, p.36]
Another word for "barn" in Old English was beretun, "barley enclosure" (from tun "enclosure, house"), which accounts for the many Barton place names on the English map, and the common surname. Barn door figurative for "broad target" and "great size" since 1540s.
Barnabas: surname of Joseph the Levite of Cyprus (Acts iv:36), literally "son of exhortation," from Aramaic bar "son" + nabha "prophecy, exhortation." St. Barnabas' Day (colloquially St. Barnaby), June 11, in the Old Style calendar was reckoned the longest day of the year.
barnacle (n.): early 13c., "species of wild goose;" as a type of "shellfish," first recorded 1580s. Often derived from a Celtic source (cf. Breton bernik, a kind of shellfish), but the application to the goose predates that of the shellfish in English. The goose nests in the Arctic in summer and returns to Europe in the winter, hence the mystery surrounding its reproduction. It was believed in ancient superstition to hatch from barnacle's shell, possibly because the crustacean's feathery stalks resemble goose down. The scientific name of the crustacean, Cirripedes, is from Greek cirri "curls of hair" + pedes "feet."
barney (n.): 1859, British slang, "lark, spree, rough enjoyment," of uncertain origin. Later also "a fixed prize-fight."
barnstorm (v.): 1815, in reference to a theatrical troupe's performances in upstate New York barns (usually featuring short action pieces to suit vulgar tastes); extended 1896 to electioneering, 1928 to itinerant airplane pilots who performed stunts at fairs and races. Related: Barnstormed; barnstorming.
barnyard (n.): 1510s, from barn + yard (n.1). Figurative of coarse or uncivilized behavior from 1920.
barometer (n.): 1660s, from Greek baros "weight" (from barys "heavy;" see grave (adj.)) + -meter. Probably coined (and certainly popularized) by English scientist Robert Boyle (1627-1691).
barometric (adj.): 1802, from barometer + -ic. Barometrical is recorded from 1660s.
baron (n.): c.1200, from Old French baron (nominative ber) "baron, nobleman, military leader, warrior, virtuous man, lord, husband," probably from or related to Late Latin baro "man," of uncertain origin, perhaps from Frankish *baro "freeman, man;" merged in England with cognate Old English beorn "nobleman."
baroness (n.): early 15c., from Old French barnesse "lady of quality, noblewoman" (also, ironically, "woman of low morals, slut") or Medieval Latin baronissa (see baron).
baronet (n.): c.1400, diminutive of baron; originally a younger or lesser baron; as a titled hereditary order, established 1611.
baronial (adj.): 1767, from baron + -ial.
barony (n.): c.1300, from Old French baronie, from Late Latin *baronia, from baron (see baron).
baroque (adj.): 1765, from French baroque (15c.) "irregular," from Portuguese barroco "imperfect pearl," of uncertain origin, perhaps related to Spanish berruca "a wart."
This style in decorations got the epithet of Barroque taste, derived from a word signifying pearls and teeth of unequal size. [Fuseli's translation of Winkelmann, 1765]
Klein suggests the name may be from Italian painter Federigo Barocci (1528-1612), a founder of the style. How to tell baroque from rococo, according to Fowler: "The characteristics of baroque are grandeur, pomposity, and weight; those of rococo are inconsequence, grace, and lightness." But the two terms often used without distinction for styles featuring odd and excessive ornamentation.
barouche (n.): type of four-wheeled carriage, 1801, from dialectal German barutsche, from Italian baroccio "chariot," originally "two-wheeled car," from Latin birotus "two-wheeled," from bi- "two" + rotus "wheel," from rotare "go around" (see rotary). Frenchified in English, but the word is not French.
barque (n.): variant of bark (n.2).
barrack (n.): 1680s, "temporary hut for soldiers during a siege," from French barraque, from Spanish barraca (mid-13c. in Medieval Latin) "soldier's tent," literally "cabin, hut," perhaps from barro "clay, mud," which is probably of Celt-Iberian origin. Meaning "permanent building for housing troops" (usually in plural) is attested from 1690s.
barracks (n.): plural, and usual, form of barrack (q.v.).
barracuda (n.): 1670s, from American Spanish barracuda, perhaps from a Carib word.
barrage (n.): 1859, "action of barring; man-made barrier in a stream," from French barrer "to stop," from barre "bar," from Old French barre (see bar (n.1)). Artillery sense is 1916, from World War I French phrase tir de barrage "barrier fire" intended to isolate the objective. As a verb by 1917. Related: Barraged; barraging.
barratry (n.): early 15c., "sale of ecclesiastical or state offices," from Old French baraterie "deceit, guile, trickery," from barat "malpractice, fraud, deceit, trickery," of unknown origin, perhaps from Celtic. In marine law, "wrongful conduct by a ship's crew or officer, resulting in loss to owners," from 1620s. Meaning "offense of habitually starting legal suits" is from 1640s. Sense somewhat confused with that of Middle English baratri "combat, fighting" (c.1400), from Old Norse baratta "fight, contest strife." This was an active word in Middle English, with forms such as baraten "to disturb the peace" (mid-15c.); baratour "inciter to riot, bully" (late 14c., mid-13c. as a surname). Barataria Bay, Louisiana, U.S., is from Spanish baratear "to cheat, deceive," cognate of the French word; the bay so called in reference to the difficulty of its entry passages.
barre: 1876, in reference to chords played on a guitar, etc., from French, literally "bar" (see bar (n.1)).
barrel (n.): c.1300, from Old French baril (12c.) "barrel, cask, vat," with cognates in all Romance languages (e.g. Italian barile, Spanish barril), but origin uncertain; perhaps from Gaulish, perhaps somehow related to bar (n.1). Meaning "metal tube of a gun" is from 1640s. Barrel roll in aeronautics is from 1927.
barrel (v.): mid-15c., "to put in barrels," from barrel (n.). Meaning "to move quickly" is 1930, American English slang, perhaps suggestive of a rolling barrel. Related: Barreled; barreling.
barrelful (n.): late 14c., from barrel (n.) + -ful.
barrelhouse (n.): "cheap saloon, often with an associated brothel," by 1875, American English, so called in reference to the barrels of beer or booze typically stacked along the wall. See barrel (n.) + house (n.).
Q. What was this place you rented? -- A. It was a room adjoining a barrel-house.
Q. What is a barrel house? -- A. It is a room where barrels of whisky are tapped, a very inferior kind of whisky, and the whisky is sold by the glassful right out of the barrel. It is a primitive coffee house. [Committee Report of the 43rd Congress, Select Committee on Conditions of the South, 1874-75]
barren (adj.): c.1200, from Old French baraigne, baraing "sterile, barren" (12c.), perhaps originally brahain, of obscure derivation, perhaps from a Germanic language. In England, originally used of women, of land in France. Of land in English from late 14c. As a noun, mid-13c., "a barren woman;" later of land.
barrenness (n.): late 14c., literal; mid-14c., figurative (of spiritual emptiness), from barren + -ness.
barret (n.): type of flat cap, 1828, from French barrette, cognate with Spanish birreta, Italian beretta (see biretta).
barrette (n.): "bar clip for women's hair," 1901, from French barrette, diminutive of barre "bar" (see bar (n.1)).
barricade (v.): 1590s, from Middle French barricader "to barricade" (1550s), from barrique "barrel," from Spanish barrica "barrel," from baril (see barrel). Revolutionary associations began during 1588 Huguenot riots in Paris, when large barrels filled with earth and stones were set up in the streets. Related: Barricaded; barricading.
barricade (n.): 1640s, from barricade (v.). Earlier was barricado (1580s) with false Spanish ending (see -ado).
barrier (n.): early 14c., barere, from Anglo-French barrere, Old French barriere "obstacle, gatekeeper," from barre "bar" (see bar (n.1)). First record of barrier reef is from 1805.
barring (n.): late 14c., "act of fastening with a bar," verbal noun from bar (v.). Meaning "exclusion" is from 1630s. As a preposition, "excepting, excluding," it is from late 15c. Schoolhouse prank of barring out the teacher was in use before 1728.
barrio (n.): 1841, "ward of a Spanish or Spanish-speaking city," sometimes also used of rural settlements, from Spanish barrio "district, suburb," from Arabic barriya "open country" (fem.), from barr "outside" (of the city). Main modern sense of "Spanish-speaking district in a U.S. city" is 1939; original reference is to Spanish Harlem in New York City.
barrister (n.): 1540s, "a student of law who has been called to the bar," from bar (n.3) in the legal sense + -ster. Also see attorney. The second element is obscure.
barroom (n.): 1797, from bar (n.2) + room (n.).
barrow (n.1): "vehicle for carrying a load," c.1300, barewe, probably from an unrecorded Old English *bearwe "basket, barrow," from beran "to bear, to carry" (see bear (v.)). The original had no wheel and required two persons to carry it.
barrow (n.2): "mound," Old English beorg (West Saxon), berg (Anglian) "barrow, mountain, hill, mound," from Proto-Germanic *bergaz (cf. Old Saxon, Old Frisian, Old High German berg "mountain," Old North bjarg "rock"), from PIE root *bheregh- "high, elevated" (cf. Old Church Slavonic bregu "mountain, height," Old Irish brigh "mountain," Sanskrit b'rhant "high," Old Persian bard- "be high"). Obsolete except in place-names and southwest England dialect by 1400; revived by modern archaeology.
In place-names used of small continuously curving hills, smaller than a dun, with the summit typically occupied by a single farmstead or by a village church with the village beside the hill, and also of burial mounds. [Cambridge Dictionary of English Place-Names]
Meaning "mound erected over a grave" was a specific sense in late Old English. Barrow-wight first recorded 1869 in Eirikr Magnusson and William Morris's translation of the Icelandic saga of Grettir the Strong.
barstool (n.): also bar-stool, bar stool, 1910, from bar (n.2) + stool.
bart.: abbreviation of baronet. Attested from c.1771.
bartender (n.): also bar-tender; 1836, American English, from bar (n.2) + agent noun of tend (v.2).
barter (v.): mid-15c., apparently from Old French barater "to barter, cheat, deceive, haggle" (also, "to have sexual intercourse"), 12c., of uncertain origin, perhaps from a Celtic language (cf. Irish brath "treachery"). Connection between "trading" and "cheating" exists in several languages. Related: Bartered; bartering. The noun is first recorded 1590s, from the verb.
Bartholomew: masc. proper name, from Old French Barthelemieu, from Latin Bartholomæus, from Greek Bartholomaios, from Aramaic bar Talmay, literally "son of Talmai," from the proper name Talmai, "abounding in furrows." One of the 12 Apostles, his festival is Aug. 24. On this date in 1572 took place the massacre of Protestants in France. Bartholomew Fair was held annually from 1133 to 1855 at West Smithfield.
bas-relief (n.): 1660s, from French bas-relief, a loan-translation of Italian basso-rilievo "low relief, raised work."
basal (adj.): "relating to a base," 1828, from base (n.) + -al (1).
basalt (n.): c.1600, from Late Latin basaltes, misspelling of Latin basanites "very hard stone," from Greek basanites "a species of slate used to test gold," from basanos "touchstone." Not connected with salt. Said by Pliny ["Historia," 36.58] to be an African word, perhaps Egyptian bauhan "slate." Any hard, very dark rock would do as a touchstone; the assayer compared the streak left by the alleged gold with that of real gold or baser metals. Hence Greek basanizein "to be put to the test, examined closely, cross-examined, to be put to torture."
base (n.): "bottom, foundation, pedestal," early 14c., from Old French bas "depth" (12c.), from Latin basis "foundation," from Greek basis "step, pedestal," from bainein "to step" (see come). The military sense is from 1860. The chemical sense (1810) was introduced in French 1754 by French chemist Guillaume-François Rouelle (1703-1770). Sporting sense of "starting point" ia from 1690s, also "destination of a runner" (1812). As a "safe" spot in a tag-like game, suggested from mid-15c. (as the name of the game later called prisoner's base).
base (adj.): late 14c., "low, of little height," from Old French bas "low, lowly, mean," from Late Latin bassus "thick, stumpy, low" (used only as a cognomen in classical Latin, humilis being there the usual word for "low in stature or position"), possibly from Oscan, or Celtic, or related to Greek basson, comparative of bathys "deep." Figurative sense of "low in the moral scale" is first attested 1530s in English, earlier "servile" (1520s). Base metals (c.1600) were worthless in contrast to noble or precious metals.