brace (n.) Look up brace at Dictionary.com
early 14c., "piece of armor for the arms," also "thong, strap for fastening," from Old French brace, braz "arms," also "length measured by two arms" (12c., Modern French bras "arm, power;" brasse "fathom, armful, breaststroke"), from Latin bracchia, plural of bracchium "an arm, a forearm," from Greek brakhion "an arm" (see brachio-). Applied to various devices for fastening and tightening on notion of clasping arms. Of dogs, "a couple, a pair" from c. 1400.
bracelet (n.) Look up bracelet at Dictionary.com
mid-15c., from Old French bracelet (14c.), diminutive of bracel, from Latin bracchiale "armlet," from bracchium "an arm, a forearm," from Greek brakhion "an arm" (see brachio-).
bracer (n.) Look up bracer at Dictionary.com
early 14c., "piece of armor protecting the arm;" 1580s, "a clamp, bind, brace," from brace (n.). Figurative sense of "that which braces the nerves" is 1740; especially of alcoholic drinks from c. 1850. Related: Bracers.
brach (n.) Look up brach at Dictionary.com
"bitch hound" (archaic), mid-14c., brache, originally "hound that hunts by scent," from Old French braches "hound, hunting dog," brachez, plural of brachet, of West Germanic origin (compare Middle Dutch brache, Old High German braccho "hound, setter"), from PIE *bhrag- "to smell" (source also of Middle High German bræhen "to smell," Latin fragrare "to smell sweetly"). Italian bracco is a Germanic loan word.
brachio- Look up brachio- at Dictionary.com
before a vowel, brachi-, word-forming element meaning "arm," from Greek brakhion "arm," perhaps originally "upper arm," literally "shorter," from brakhys "short" (from PIE root *mregh-u- "short"), in contrast to the longer forearm.
brachiopod (n.) Look up brachiopod at Dictionary.com
type of bivalve mollusk, 1836, Modern Latin, from Greek brakhion "an arm" (see brachio-) + pous "foot" (from PIE root *ped- "foot"). They have long spiral "arms" on either side of their mouths.
brachiosaurus (n.) Look up brachiosaurus at Dictionary.com
1903, Modern Latin, from Greek brakhion "an arm" (see brachio-) + -saurus. The forelegs are notably longer than the hind legs.
brachy- Look up brachy- at Dictionary.com
word-forming element meaning "short," from Latinized combining form of Greek brakhys "short" (from PIE root *mregh-u- "short").
brack (adj.) Look up brack at Dictionary.com
"salty, briny," 1510s, from Dutch brak "brackish," probably from Middle Dutch brak "worthless," a word also used in commercial trade and which also made its way into early Modern English.
bracken (n.) Look up bracken at Dictionary.com
"coarse fern," early 14c., a northern England word, probably from a Scandinavian source (compare Danish bregne, Swedish bräken "fern"), from Proto-Germanic *brak- "undergrowth, bushes," from PIE root *bhreg- "to break" on the notion of "that which impedes motion" [Watkins].
bracket (v.) Look up bracket at Dictionary.com
1797, of printed matter, "to enclose in brackets," from bracket (n.). Also, "to couple or connect with a brace" (1827), also figurative, "to couple one thing with another" in writing (1807). Artillery rangefinding sense is from 1903, from the noun (1891) in the specialized sense "distance between the ranges of two shells, one under and one over the object." Related: Bracketed; bracketing. In home-building and joinery, bracketed is attested by 1801.
bracket (n.) Look up bracket at Dictionary.com
1570s, bragget, "architectural support," probably from Middle French braguette "codpiece armor" (16c.), from a fancied resemblance of architectural supports to that article of attire (Spanish cognate bragueta meant both "codpiece" and "bracket"), diminutive of brague "knee pants," ultimately from Gaulish *braca "pants," itself perhaps from Germanic (compare Old English broc "garment for the legs and trunk;" see breeches). The architectural meaning also might reflect the "breeches" sense, on the notion of two limbs or of appliances used in pairs. The typographical bracket is first recorded 1750, so called for its resemblance to double supports in carpentry (a sense attested from 1610s). Senses affected by Latin brachium "arm."
brackish (adj.) Look up brackish at Dictionary.com
1530s, from Scottish brack "salty" (see brack) + -ish. Related: Brackishness.
bract (n.) Look up bract at Dictionary.com
in botany, "small leaf at the base of a flower," Modern Latin, from Latin bractea, literally "thin metal plate," which is of unknown origin. Related: Bracteal; bracteate.
brad (n.) Look up brad at Dictionary.com
"small wire nail," late 13c., brod, from Old Norse broddr "spike, point, arrow," from Proto-Germanic *brozda- (source also of Old English brord "point, prick, blade of grass," Old High German brort "point, edge, crown"), from PIE *bhrs-dh-, from root *bhars- "projectile, point, bristle" (see bristle (n.)).
brady- Look up brady- at Dictionary.com
medical word-forming element meaning "slow, delayed, tardy," from Greek bradys "slow;" as in bradycardia (1890), with Latinized form of Greek kardia "heart;" bradykinesia, "slow movement," with Greek kinesis "movement, motion;" bradypnea, with Greek pneo/pnein "to breathe."
brae (n.) Look up brae at Dictionary.com
"steep slope," in northern England especially "the sides of a hill," early 14c., from Scottish, "slope, river bank," from Old Norse bra "eyelash," cognate with Old English bræw "eyelid," German Braue "eyebrow" (see brow). "The word must have passed through the sense of 'eye-brow' to 'brow of a hill', supercilium (cf. OE. eaghill 'eye-hill'=eyebrow)" [OED].
brag (n.) Look up brag at Dictionary.com
late 14c., "pomp; arrogance, pride;" see brag (v.); the exact relationship of the forms is uncertain. Meaning "that which is boasted" is from 1530s. As a once-popular poker-like card game, from 1734.
brag (v.) Look up brag at Dictionary.com
mid-14c., braggen "to make a loud sound," also "to talk boastfully," of obscure origin, perhaps related to bray of a trumpet, or related to the Middle English adjective brag "ostentatious, proud; spirited, brave" (early 14c.), which probably is from Celtic. Other sources suggest Old Norse bragr "the best, the toast (of anything)," also "poetry." Also see braggart for another possibility. Related: Bragged; bragging.
Braganza Look up Braganza at Dictionary.com
city in Portugal (Portuguese Bragança), from Celtic briga "height"
braggadocio (n.) Look up braggadocio at Dictionary.com
Spenser's coinage, 1590, as a name for his personification of vainglory, from brag, with augmentative ending by analogy to the Italian words then in vogue in England. In general use by 1594 for "an empty swaggerer;" of the talk of such persons, from 1734.
braggart (n.) Look up braggart at Dictionary.com
1570s, from French bragard (16c.), with pejorative ending (see -ard) + Middle French braguer "to flaunt, brag," perhaps originally "to show off clothes, especially breeches," from brague "breeches" (see bracket). There may be an element of codpiece-flaunting in all this.

The word in English has been at least influenced by brag (v.), even if, as some claim, it is unrelated to it. Bragger "arrogant or boastful person," agent noun from brag (v.), attested in English from late 14c.
Brahma Look up Brahma at Dictionary.com
1785, from Sanskrit Brahma, nominative of Brahman, chief god of the trinity Brahma-Vishnu-Siva in post-Vedic Hindu religion (see brahmin).
Brahman Look up Brahman at Dictionary.com
see brahmin.
Brahmaputra Look up Brahmaputra at Dictionary.com
river in Asia, Hindi, literally "son of Brahma."
brahmin (n.) Look up brahmin at Dictionary.com
"member of Boston's upper class," 1823, figurative use of Brahman "member of the highest priestly Hindu caste," late 15c., from Sanskrit brahmana-s, from brahman- "prayer," also "the universal soul, the Absolute," which is of uncertain origin. Related to Brahma.
braid (n.) Look up braid at Dictionary.com
in part from stem found in Old English gebrægd "craft, fraud," gebregd "commotion," Old Norse bragð "deed, trick," and in part from or influenced by related braid (v.). Earliest senses are "a deceit, stratagem, trick" (c. 1200), "sudden or quick movement" (c. 1300); meaning "anything plaited or entwined" (especially hair) is from 1520s.
braid (v.) Look up braid at Dictionary.com
"to plait, knit, weave, twist together," c. 1200, breidan, from Old English bregdan "to move quickly, pull, shake, swing, throw (in wrestling), draw (a sword); bend, weave, knit, join together; change color, vary; scheme, feign, pretend" (class III strong verb, past tense brægd, past participle brogden), from Proto-Germanic *bregthan "make sudden jerky movements from side to side" (compare Old Norse bregða "to brandish, turn about, braid;" Old Saxon bregdan "to weave;" Dutch breien "to knit;" Old High German brettan "to draw, weave, braid"), from PIE root *bherek- "to gleam, flash" (compare Sanskrit bhrasate "flames, blazes, shines"). In English the verb survives only in the narrow definition of "plait hair." Related: Braided; braiding.
braids (n.) Look up braids at Dictionary.com
1520s; see braid (n.).
brail (n.) Look up brail at Dictionary.com
small rope used on ships, mid-15c., from Old French brail, earlier braiel "belt, leather thong," from Latin bracale "waistbelt," from bracæ "breeches" (plural, see breeches).
Braille Look up Braille at Dictionary.com
1853, from Louis Braille (1809-1852), French musician and teacher, blind from age 3, who devised it c. 1830.
brain (v.) Look up brain at Dictionary.com
"to dash the brains out," late 14c., from brain (n.). Related: Brained; braining.
brain (n.) Look up brain at Dictionary.com
Old English brægen "brain," from Proto-Germanic *bragnam (source also of Middle Low German bregen, Old Frisian and Dutch brein), from PIE root *mregh-m(n)o- "skull, brain" (source also of Greek brekhmos "front part of the skull, top of the head"). But Liberman writes that brain "has no established cognates outside West Germanic ..." and is not connected to the Greek word. More probably, he writes, its etymon is PIE *bhragno "something broken."

The custom of using the plural to refer to the substance (literal or figurative), as opposed to the organ, dates from 16c. Figurative sense of "intellectual power" is from late 14c.; meaning "a clever person" is first recorded 1914. Brain teaser is from 1923. Brain stem first recorded 1879, from German. Brain drain is attested from 1963. An Old English word for "head" was brægnloca, which might be translated as "brain locker." In Middle English, brainsick (Old English brægenseoc) meant "mad, addled."
brain trust (n.) Look up brain trust at Dictionary.com
occasionally used since early 1900s, it became current in 1933, in reference to the intellectuals gathered by U.S. President Franklin D. Roosevelt as advisors; from brain (n.) + trust (n.).
brain-child (n.) Look up brain-child at Dictionary.com
"idea, creation of one's own," 1881, from brain (n.) + child. Earlier was the more alliterative brain-brat (1630).
brain-dead (adj.) Look up brain-dead at Dictionary.com
1976, popularized in U.S. by the Karen Anne Quinlan case (brain death is from 1968).
brainiac (n.) Look up brainiac at Dictionary.com
"very smart person," 1982, U.S. slang, from brain (n.) + ending from ENIAC, etc. Brainiac also was the name of a comic book villain in the Superman series and a do-it-yourself computer building kit, both from the late 1950s, and the word may bear traces of either or both of these.
brainstorm (n.) Look up brainstorm at Dictionary.com
"brilliant idea, mental excitement, fit of mental application," 1849, from brain (n.) + figurative use of storm (n.). As a verb, recorded from 1920s. Related: Brainstormed; brainstorming.
brainwash (v.) Look up brainwash at Dictionary.com
1955 (past participle adjective brainwashed attested from 1953); see brainwashing.
brainwashing (n.) Look up brainwashing at Dictionary.com
1950, a literal translation of Chinese xi nao. A term from the Korean War.
brainy (adj.) Look up brainy at Dictionary.com
1845, from brain (n.) + -y (2). Latin equivalent cerebrosus meant "passionate, hot-headed," leading Tucker to remark that " 'Brainy' is not a natural expression for 'frantic.' "
braise (v.) Look up braise at Dictionary.com
1797, from French braiser "to stew" (17c.), from braise "live coals," from Old French brese "embers" (12c.), ultimately from West Germanic *brasa (as is Italian bragia, Spanish brasa), from PIE root *bhreu- "to boil, bubble, effervesce, burn." Related: Braised; braising.
brake (n.1) Look up brake at Dictionary.com
mid-15c., "instrument for crushing or pounding," from Middle Dutch braeke "flax brake," from breken "to break" (see break (v.)). The word was applied to many crushing implements and to the ring through the nose of a draught ox. It was influenced in sense by Old French brac, a form of bras "an arm," thus "a lever or handle," which was being used in English from late 14c., and applied to "a bridle or curb" from early 15c. One or the other or both took up the main modern meaning of "stopping device for a wheel," first attested 1772.
brake (n.2) Look up brake at Dictionary.com
kind of fern, early 14c.; see bracken.
brake (v.) Look up brake at Dictionary.com
"to apply a brake to a wheel," 1868, from brake (n.1). Earlier, "to beat flax" (late 14c.). Related: Braked; braking.
bramble (n.) Look up bramble at Dictionary.com
Old English bræmbel "rough, prickly shrub" (especially the blackberry bush), with euphonic -b-, from earlier bræmel, from Proto-Germanic *bræmaz (see broom).
bran (n.) Look up bran at Dictionary.com
c. 1300, "the husk of wheat, barley, etc., separated from the flour after grinding," from Old French bren "bran, scurf, scales, feces" (12c., Modern French bran), perhaps connected with Gaulish *brenno- "manure," or with burn (v.). The word also was used 16c. in English for "dandruff flakes."
branch (v.) Look up branch at Dictionary.com
"send out shoots or new limbs," late 14c., also, of blood vessels, family trees, etc., "to be forked," from branch (n.). Meaning "to spread out from a center, radiate" is from c. 1400. Related: Branched; branching.
branch (n.) Look up branch at Dictionary.com
c. 1300, braunch, "limb of a tree" (also used of things analogous to it, especially geographic features), from Old French branche "branch, bough, twig; branch of a family" (12c.), from Late Latin branca "footprint," later "a claw, paw," which is of unknown origin, probably from Gaulish. The connecting notion would be the shape (compare pedigree). Replaced native bough. Meaning "local office of a business" is first recorded 1817, from earlier sense of "component part of a system" (1690s).
brand (v.) Look up brand at Dictionary.com
c. 1400, "to brand, cauterize; stigmatize," originally of criminal marks or cauterized wounds, from brand (n.). As a means of marking property, 1580s; figuratively from c. 1600, often in a bad sense, with the criminal marking in mind. Related: Branded; branding.