Online Etymology Dictionary

bandy (v.): 1570s, "to strike back and forth," from Middle French bander, from root of band (n.2). The sense apparently evolved from "join together to oppose," to opposition itself, to "exchanging blows," then metaphorically, to volleying in tennis. Bandy (n.) was a 17c. Irish game, precursor of field hockey, played with a curved stick (also called a bandy), hence bandy-legged (1680s).
bane (n.): Old English bana "killer, slayer, murderer; the devil," from Proto-Germanic *banon, cognate with *banja- "wound" (source also of Old Frisian bona "murderer," Old Norse bani, Old High German bana "murder," Old English benn "wound," Gothic banja "stroke, wound"), from PIE root *gwhen- "to strike, kill, wound" (source also of Avestan banta "ill"). Modern sense of "that which causes ruin or woe" is from 1570s.
bang (v.): 1540s, "to strike hard with a loud blow," from a Scandinavian sourse akin to Old Norse banga "to pound, hammer" of echoic origin. Slang meaning "have sexual intercourse with" first recorded 1937. Bang-up "excellent, first-rate," 1820, probably shortened from phrase bang up to the mark. The noun is recorded from late 16c.
This is the way the world ends
Not with a bang but a whimper

[T.S. Eliot, "Hollow Men," 1925]
banger (n.): British English slang for "a sausage," 1919, perhaps from sense of "a bludgeon," though this is recorded only in U.S. slang.
Bangladesh: nation formed 1971 from former East Pakistan, from Bengali for "Bengali country," from Bangla "Bengali" + desh "country."
bangle (n.): "ring-shaped bracelet," 1787, from Hindi bangri "colored glass bracelet or anklet."
bangs (n.): "hair cut straight across the forehead," 1878 (singular), American English, attested from 1870 of horses (bang-tail), perhaps from notion of abruptness (as in bang off "immediately, without delay," though this expression is attested only from 1886). See bang.
banish (v.): late 14c., banischen, from banniss-, extended stem of Old French banir "announce, proclaim; levy; forbid; banish, proclaim an outlaw," from a Germanic source (perhaps Frankish *bannjan "to order or prohibit under penalty"), or from Vulgar Latin cognate *bannire (see bandit). Related: Banished; banishing.
banishment (n.): c. 1500, from banish + -ment.
banister (n.): 1660s, unexplained corruption of baluster. As late as 1830 condemned as "vulgar," it is now accepted. Surname Bannister is from Old French banastre "basket," hence, "basket-maker."
banjo (n.): 1764, in various spellings (Jefferson has banjar), American English, usually described as of African origin, probably akin to Bantu mbanza, an instrument resembling a banjo. The word has been influenced by colloquial pronunciation of bandore (1560s in English), a 16c. stringed instrument like a lute and an ancestor (musically and linguistically) of mandolin; from Portuguese bandurra, from Latin pandura, from Greek pandoura "three-stringed instrument." The origin and influence might be the reverse of what is here described.
bank (n.1): "financial institution," late 15c., from either Old Italian banca or Middle French banque (itself from the Italian word), both meaning "table" (the notion is of the moneylender's exchange table), from a Germanic source (compare Old High German bank "bench"); see bank (n.2).

Bank holiday is from 1871, though the tradition is as old as the Bank of England. To cry all the way to the bank was coined 1956 by flamboyant pianist Liberace, after a Madison Square Garden concert that was packed with patrons but panned by critics.
bank (n.2): "earthen incline, edge of a river," c. 1200, probably in Old English but not attested in surviving documents, from a Scandinavian source such as Old Norse banki, Old Danish banke "sandbank," from Proto-Germanic *bangkon "slope," cognate with *bankiz "shelf" (see bench (n.)).
bank (v.): "to act as a banker," 1727, from bank (n.1). As "to deposit in a bank" from 1833. Figurative sense of "to rely on" (i.e. "to put money on") is from 1884, U.S. colloquial. Meaning "to ascend," as of an incline, is from 1892. In aeronautics, from 1911. Related: Banked; banking.
banker (n.): "keeper of a bank," 1530s, agent noun formed from bank (n.1), possibly modeled on French banquier (16c.).
banking (n.): "business of a banker," 1735, verbal noun from bank (v).
bankroll (n.): "roll of bank notes," 1887, from bank (n.1) + roll (n.). The verb is attested from 1928. Related: Bankrolled; bankrolling.
bankrupt (adj.): 1560s, from Italian banca rotta, literally "a broken bench," from banca "moneylender's shop," literally "bench" (see bank (n.1)) + rotta "broken, defeated, interrupted" from (and remodeled on) Latin rupta, fem. past participle of rumpere "to break" (see rupture (n.)). "[S]o called from the habit of breaking the bench of bankrupts" [Klein]. Earlier in English as a noun, "bankrupt person" (1530s).
bankrupt (v.): 1550s, from bankrupt (adj.). Related: Bankrupted; bankrupting.
bankruptcy (n.): 1700, from bankrupt, "probably on the analogy of insolvency, but with -t erroneously retained in spelling, instead of being merged in the suffix ...." [OED]. Figurative use from 1761.
banlieue (n.): French, "suburbs, precincts," from Vulgar Latin *banleuca, from ban (see ban (n.1)) + leuca "a league (of distance)," in Medieval Latin, "indefinite extent of territory" (see league (n.2)). So, "the extent of a ban; the territory within which a ban is of force," hence, "territory subject to one jurisdiction."
bann (n.): in phrase banns of marriage (late 12c., spelling with double -n- attested from 1540s), from Old English bannan "to summon, command, proclaim" (see ban (v.)). Also probably partly from Old French ban "announcement, proclamation, banns, authorization," from Frankish *ban or some other Germanic cognate of the Old English word.
banner (n.): c. 1200, from Old French baniere (Modern French bannière) "flag, banner, standard," from Late Latin bandum "standard," borrowed from a West Germanic cognate of Gothic bandwa "a sign" (see band (n.2)). Figurative use from early 14c. Of newspaper headlines, from 1913.
banneret (n.): c. 1300, an order of knighthood, originally in reference to one who could lead his men into battle under his own banner. Later it meant one who received rank for valiant deeds done in the king's presence in battle. Also "a small banner" (c. 1300).
bannock (n.): "thick flat cake," Old English bannuc "a bit, small piece," from Gaelic bannach "a cake," perhaps a loan from Latin panicium, from panis "bread," from PIE root *pa- "to feed" (see food).
banns (n.): see bann.
banquet (n.): late 15c., "feast, sumptuous entertainment," from French banquet (15c.; in Old French only "small bench"), from Old Italian banchetto, diminutive of banco "bench;" originally a snack eaten on a bench (rather than at table), hence "a slight repast between meals;" the meaning has entirely reversed. As a verb from 1510s.
banquette (n.): 1620s, "raised platform in a fortification," from French banquette (15c.), from Italian banchetta, diminutive of banca "bench, shelf" (see bank (n.1)).
banshee (n.): 1771, from phonetic spelling of Irish bean sidhe "female of the Elves," from bean "woman" (from PIE *gwen-; see queen) + sidhe, from sith "fairy" or sid "fairy mound." Specifically, one who calls to the spirits of the dead. Sidhe sometimes is confused with sithe, genitive of sith "peace."
bantam (n.): 1749, after Bantam, former Dutch residency in Java, from which the small domestic fowl were said to have been first imported. Extension to "small person" is 1837. As a light weight class in boxing, it is attested from 1884, probably from the birds, which are small but aggressive and bred for fighting.
banter (v.): 1670s, origin uncertain; said by Swift to be a word from London street slang. Related: Bantered; bantering. The noun is from 1680s.
Banting (n.): system for weight loss through diet control, named for William Banting (1797-1878), English undertaker who invented it, tested it himself, and promoted it in his 1863 booklet "Letter on Corpulence, Addressed to the Public." Although the word is a surname, it was used like a verbal noun in -ing. ("She is banting").
Bantu: 1862, applied to south African language group in the 1850s by German linguist Wilhelm Heinrich Immanuel Bleek (1827-1875), from native Ba-ntu "mankind," from ba-, plural prefix, + ntu "a man, person." Bantustan in a South African context is from 1949.
banyan (n.): "Indian fig tree," 1630s, so called in reference to a tree on the Iranian coast of the Persian Gulf under which the Hindu merchants known as banians had built a pagoda. From Sanskrit vanija "merchant."
banzai: Japanese war-cry, 1893, literally "(may you live) ten thousand years," originally a greeting addressed to the emperor, from ban "ten thousand" + sai "year."
baobab (n.): 1630s, from Medieval Latin bahobab (1590s), apparently from a central African language.
baptise (v.): chiefly British English spelling of baptize; for spelling, see -ize. Related: Baptised; baptising.
baptism (n.): c. 1300, bapteme, from Old French batesme, bapteme (11c., Modern French baptême), from Latin baptismus, from Greek baptismos, noun of action from baptizein (see baptize). The -s- restored in later 14c.

Figurative sense is from late 14c. The Anglo-Saxons used fulluht in this sense (John the Baptist was Iohannes se Fulluhtere). Phrase baptism of fire "a soldier's first experience of battle" (1857) translates French baptême de feu; the phrase originally was ecclesiastical Greek baptisma pyros and meant "the grace of the Holy Spirit as imparted through baptism." Later it was used of martyrdom, especially by burning.
baptismal (adj.): 1640s, from baptism + -al (1).
baptist (n.): c. 1200, "one who baptizes;" see baptize + -ist. As "member of a Protestant sect that believes in adult baptism by immersion" (with capital B-), attested from 1654; their opponents called them anabaptists.
baptize (v.): c. 1300, from Old French batisier (11c.), from Latin baptizare, from Greek baptizein "immerse, dip in water," also figuratively, "be over one's head" (in debt, etc.), "to be soaked (in wine);" in Greek Christian usage, "baptize;" from baptein "to dip, steep, dye, color," from PIE root *gwabh- "to dip, sink." Christian baptism originally consisted in full immersion. Related: Baptized; baptizing.
Baqubah: city in Iraq, from Arabic baya 'kuba "Jacob's house."
bar (n.1): late 12c., "stake or rod of iron used to fasten a door or gate," from Old French barre (12c.) "beam, bar, gate, barrier," from Vulgar Latin *barra "bar, barrier," which some suggest is from Gaulish *barros "the bushy end" [Gamillscheg], but OED regards this as "discredited" because it "in no way suits the sense." Of soap, by 1833; of candy, by 1906 (the process itself dates to the 1840s). Meaning "bank of sand across a harbor or river mouth" is from 1580s, probably so called because it was an obstruction to navigation. Bar graph is attested from 1925. Bar code first recorded 1963. Behind bars "in prison" is attested by 1934, U.S.
bar (n.2): "tavern," 1590s, so called in reference to the bars of the barrier or counter over which drinks or food were served to customers (see bar (n.1)).
bar (n.3): "whole body of lawyers, the legal profession," 1550s, a sense which derives ultimately from the railing that separated benchers from the hall in the Inns of Court. Students who had attained a certain standing were "called" to it to take part in the important exercises of the house. After c. 1600, however, this was popularly assumed to mean the bar in a courtroom, which was the wooden railing marking off the area around the judge's seat, where prisoners stood for arraignment and where a barrister (q.v.) stood to plead. As the place where the business of court was done, bar in this sense had become synonymous with "court" by early 14c.
bar (n.4): unit of pressure, coined 1903 from Greek baros "weight," related to barys "heavy," from PIE root *gwere- (2) "heavy" (see grave (adj.)).
bar (v.): c. 1300, "to fasten (a gate, etc.) with a bar," from bar (n.1); sense of "to obstruct, prevent" is recorded by 1570s. Expression bar none "without exception" is recorded from 1866.
Bar Mitzvah: 1861, in Judaism, "male person who has completed his 13th year and thus reached the age of religious responsibility," from Hebrew, literally "son of command." As a name for the ceremony itself, by 1941.
Barabbas: biblical masc. proper name, Greek Barabbas, from Aramaic barabba, "son of the father," or "son of the master." In Hebrew, it would be ben abh.
barb (n.): late 14c., "barb of an arrow," from Old French barbe (11c.) "beard, beardlike appendage," from Latin barba "beard," perhaps cognate with Old English beard (see beard (n.)).