bulldog (n.) Look up bulldog at Dictionary.com
c. 1500, from bull (n.1) + dog (n.). Perhaps from shape, perhaps because originally used for baiting bulls.
bulldoze (v.) Look up bulldoze at Dictionary.com
by 1880, from an earlier noun, bulldose "a severe beating or lashing" (1876), literally "a dose fit for a bull," a slang word referring to the intimidation beating of black voters (by either blacks or whites) in the chaotic 1876 U.S. presidential election. See bull (n.1) + dose (n.). Related: Bulldozed; bulldozing.
bulldozer (n.) Look up bulldozer at Dictionary.com
"person who intimidates by violence," 1876, agent noun from bulldoze (q.v.). Meaning extended to ground-clearing caterpillar tractor in 1930.
bullet (n.) Look up bullet at Dictionary.com
1550s, from Middle French boulette "cannonball, small ball," diminutive of boule "a ball" (13c.), from Latin bulla "round thing, knob" (see bull (n.2)). Earliest version of bite the bullet recorded 1891, probably with a sense of giving someone a soft lead bullet to clench in the teeth during a painful operation.
bulletin (n.) Look up bulletin at Dictionary.com
1765, from French bulletin (16c.), modeled on Italian bulletino, diminutive of bulletta "document, voting slip," itself a diminutive of Latin bulla (see bull (n.2)) with equivalent of Old French -elet (see -let). The word was used earlier in English in the Italian form (mid-17c.). Popularized by their use in the Napoleonic Wars as the name for dispatches sent from the front and meant for the home public (which led to the proverbial expression as false as a bulletin). Bulletin board is from 1831.
bullfinch (n.) Look up bullfinch at Dictionary.com
1560s, from bull (n.1) + finch; supposedly so called for the shape of its head and neck; compare French bouvreuil.
bullfrog (n.) Look up bullfrog at Dictionary.com
also bull-frog, 1738, from bull (n.1) + frog (n.1). So called for its voice.
bullied (adj.) Look up bullied at Dictionary.com
1851, past participle adjective from bully (v.).
bullion (n.) Look up bullion at Dictionary.com
early 15c., "uncoined gold or silver," from Anglo-French bullion "bar of precious metal," also "place where coins are made, mint," perhaps, through the notion of "melting," from Old French boillir "to boil," from Latin bullire "boil" (see boil (v.)). But perhaps it is rather from Old French bille "stick, block of wood" (see billiards).
bullish (adj.) Look up bullish at Dictionary.com
1560s, from bull (n.1) + -ish; stock market sense is from 1882. Related: Bullishly; bullishness.
bullock (n.) Look up bullock at Dictionary.com
Old English bulluc "young bull," from Proto-Germanic *bulluka-, from the stem of bull (n.1). Now always a castrated bull reared for beef.
bullpen (n.) Look up bullpen at Dictionary.com
also bull-pen, 1915, in the baseball sense, from bull (n.1) + pen (n.2); perhaps from earlier slang meaning "temporary holding cell for prisoners" (1809). Bullpen also was the name of a baseball-like game played in U.S. late 19c.
bullseye (n.) Look up bullseye at Dictionary.com
also bulls-eye, 1833, "center of a target," from bull (n.1) + eye (n.). So called for size and color. Meaning "shot that hits the mark" is from 1857.
bullshit (n.) Look up bullshit at Dictionary.com
"eloquent and insincere rhetoric," 1915, American English slang; see bull (n.1) + shit (n.), probably because it smells. But bull in the sense of "trivial or false statements" (1914), which usually is associated with this, might be a continuation of Middle English bull "false talk, fraud" (see bull (n.3)).
bullshit (v.) Look up bullshit at Dictionary.com
by 1942, from bullshit (n.). Related: Bullshitted; bullshitting.
bully (v.) Look up bully at Dictionary.com
1710, from bully (n.). Related: Bullied; bullying.
bully (n.) Look up bully at Dictionary.com
1530s, originally "sweetheart," applied to either sex, from Dutch boel "lover; brother," probably a diminutive of Middle Dutch broeder "brother" (compare Middle High German buole "brother," source of German Buhle "lover;" see brother (n.)).

Meaning deteriorated 17c. through "fine fellow" and "blusterer" to "harasser of the weak" (1680s, from bully-ruffian, 1650s). Perhaps this was by influence of bull (n.1), but a connecting sense between "lover" and "ruffian" may be in "protector of a prostitute," which was one sense of bully (though not specifically attested until 1706). "Sweetheart" words often go bad in this way; compare leman, also ladybird, which in Farmer & Henley is "1. A whore; and (2) a term of endearment." The expression meaning "worthy, jolly, admirable" (especially in 1864 U.S. slang bully for you!) is first attested 1680s, and preserves an earlier, positive sense of the word.
bully pulpit (n.) Look up bully pulpit at Dictionary.com
1904, coined by U.S. president Teddy Roosevelt, in reference to the White House.
bullying (n.) Look up bullying at Dictionary.com
1802, verbal noun from bully (v.).
bulrush (n.) Look up bulrush at Dictionary.com
also bullrush, type of tall plant growing in or near water (in Biblical use, the Egyptian papyrus), mid-15c., bolroysche, from rush (n.); the signification of bull is doubtful.
bulwark (n.) Look up bulwark at Dictionary.com
"planking or woodwork round the uppermost parts of a vessel," early 15c., from Middle Dutch bulwerke or Middle High German bolwerc, probably from bole "plank, tree trunk" (from Proto-Germanic *bul-, from PIE root *bhel- (2) "to blow, swell") + werc "work" (see work (n.)). Figurative sense "means of defense or security" is from 1570s. A doublet of boulevard.
bum (v.) Look up bum at Dictionary.com
1863, "to loaf and beg," American English, a word from the Civil War, perhaps a back-formation from bummer "loafer," or from bum (n.). Meaning "to feel depressed" is from 1973, perhaps from bummer in the "bad experience" sense. Related: Bummed; bumming.
bum (adj.) Look up bum at Dictionary.com
"of poor quality," 1859, American English, from bum (n.). Bum steer in figurative sense of "bad advice" attested from 1901.
bum (n.1) Look up bum at Dictionary.com
"buttocks," late 14c., "probably onomatopœic, to be compared with other words of similar sound and with the general sense of 'protuberance, swelling.' " [OED]
bum (n.2) Look up bum at Dictionary.com
"dissolute loafer, tramp," 1864, American English, from bummer "loafer, idle person" (1855), probably from German slang bummler "loafer," from bummeln "go slowly, waste time." Bum first appears in a German-American context, and bummer was popular in the slang of the North's army in the American Civil War (as many as 216,000 German immigrants in the ranks). Bum's rush "forcible ejection" first recorded 1910.
bumbailiff (n.) Look up bumbailiff at Dictionary.com
server of writs, maker of arrests, etc., c. 1600, from bum "arse" (see bum (n.1)), because he was always felt to be close behind, + bailiff.
bumble (v.) Look up bumble at Dictionary.com
"to flounder, blunder," 1530s, probably of imitative origin. Related: Bumbled; bumbler; bumbling.
Bumble Look up Bumble at Dictionary.com
"self-important petty official," 1856, from the name of the fussy, pompous, stupid beadle in Dickens' "Oliver Twist."
bumblebee (n.) Look up bumblebee at Dictionary.com
also bumble-bee, 1520s, replacing Middle English humbul-be (altered by association with Middle English bombeln "to boom, buzz," late 14c.); echoic, from PIE echoic root *kem "to hum."
bumf (n.) Look up bumf at Dictionary.com
"papers, paperwork," 1889, British schoolboy slang, originally "toilet-paper," from bum-fodder.
bummer (n.) Look up bummer at Dictionary.com
"loafer, idle person," 1855, possibly an extension of the British word for "backside" (similar development took place in Scotland by 1540), but more probably from German slang bummler "loafer," agent noun from bummeln "go slowly, waste time."

According to Kluge, the German word is from 17c., and the earliest sense of it is "oscillate back and forth;" possibly connected to words in German for "dangle" (baumeln), via "back-and-forth motion" of a bell clapper, transferred to "going back and forth," hence "doing nothing." Meaning "bad experience" is 1968 slang.
bump (v.) Look up bump at Dictionary.com
1560s, "to bulge out;" 1610s, "to strike heavily," perhaps from Scandinavian, probably echoic, original sense was "hitting" then of "swelling from being hit." Also has a long association with obsolete bum "to make a booming noise," which perhaps influenced surviving senses such as bumper crop, for something full to the brim (see bumper). To bump into "meet" is from 1880s; to bump off "kill" is 1908 in underworld slang. Related: Bumped; bumping. Bumpsy (adj.) was old slang for "drunk" (1610s).
bump (n.) Look up bump at Dictionary.com
1590s, "protuberance caused by a blow;" 1610s as "a dull, solid blow;" see bump (v.). The dancer's bump and grind attested from 1940.
bumper (n.) Look up bumper at Dictionary.com
1670s, "glass filled to the brim;" perhaps from notion of bumping as "large," or from a related sense of "booming" (see bump (v.)). Meaning "anything unusually large" is from 1759, slang. Agent-noun meaning "buffer of a car" is from 1839, American English, originally in reference to railway cars; 1901 of automobiles (in phrase bumper-to-bumper, in reference to a hypothetical situation; of actual traffic jams by 1908).
bumpkin (n.) Look up bumpkin at Dictionary.com
"awkward country fellow," 1560s, probably from Middle Dutch bommekijn "little barrel," diminutive of boom "tree" (see beam (n.)). Apparently, though itself Dutch, it began as a derogatory reference to Dutch people as short and dumpy.
bumptious (adj.) Look up bumptious at Dictionary.com
"assertive," 1803, probably a humorous coinage from bump on the pattern of fractious, etc. Related: Bumptiously; bumptiousness.
bumpy (adj.) Look up bumpy at Dictionary.com
1865, from bump + -y (2).
Fasten your seatbelts. It's going to be a bumpy night. [Bette Davis ("Margo Channing"), "All About Eve," 1950]
Related: Bumpiness.
bun (n.) Look up bun at Dictionary.com
late 14c., origin obscure, perhaps from Old French buignete "a fritter," originally "boil, swelling," diminutive of buigne "swelling from a blow, bump on the head," from a Germanic source (compare Middle High German bunge "clod, lump"), or from Gaulish *bunia (compare Gaelic bonnach). Spanish buñelo "a fritter" apparently is from the same source. Of hair coiled at the back of the head, first attested 1894. To have a bun in the oven "be pregnant" is from 1951.

The first record of buns in the sense of "male buttocks" is from 1960s, perhaps from a perceived similarity; but bun also meant "tail of a hare" (1530s) in Scottish and northern England dialect and was transferred to human beings (and conveniently rhymed with nun in ribald ballads). This may be an entirely different word; OED points to Gaelic bun "stump, root."
buna (n.) Look up buna at Dictionary.com
synthetic rubber made from butadiene, from German Buna, from first elements of butadiene, name of a hydrocarbon (related to butane; the suffix indicates the presence of two double bonds) + Na, indicating sodium (from natrium; see sodium).
bunch (v.) Look up bunch at Dictionary.com
"to bulge out," late 14c., from bunch (n.). Meaning "to gather up in a bunch" (transitive) is from 1828; sense of "to crowd together" (intransitive) is from 1873. Related: Bunched; bunching.
bunch (n.) Look up bunch at Dictionary.com
early 14c., "protuberance on the body, swelling," perhaps echoic of the sound of hitting and connected to bump (compare, possibly in similar relationship, hump/hunch).

The sense of "cluster" is mid-15c.; connection with the earlier sense is obscure, and this may be a separate word, perhaps through a nasalized form of Old French bouge (2), 15c., from Flemish boudje diminutive of boud "bundle." Meaning "a lot, a group" is from 1620s.
buncombe (n.) Look up buncombe at Dictionary.com
see bunk (n.2).
bund (n.) Look up bund at Dictionary.com
"league, confederacy," 1850, from German Bund (related to English band (n.2) and bind (v.)). In names of various fraternal organizations, in U.S. especially the German-American Bund, pro-Nazi organization founded 1936.
Bundestag (n.) Look up Bundestag at Dictionary.com
German federal council, 1879, from German Bundestag, from genitive of Bund "league, confederacy, association" (related to English band (n.2) and bind (v.)) + tag, literally "day;" as a verb, tagen, meaning "to sit in conference" (see day; also compare adjourn). Hence also Bundesrat, from rat, rath "council" (see read (v.)).
bundle (v.) Look up bundle at Dictionary.com
1620s, "to make into a bundle," from bundle (n.); meaning "to wrap up in warm heavy clothes" is from 1893. Meaning "to sleep with another, clothed, in the same bed," a noted former custom in New England, is from 1781. Meaning "to send away hurriedly" is from 1823. Related: Bundled; bundling.
bundle (n.) Look up bundle at Dictionary.com
early 14c., "bound collection of things," from Middle Dutch bondel, diminutive of bond, from binden "to bind," or perhaps a merger of this word and Old English byndele "binding," from Proto-Germanic *bundilin (source also of German bündel "to bundle"), from PIE root *bhendh- "to bind." Meaning "a lot of money" is from 1899. To be a bundle of nerves "very anxious" is from 1938.
bundling (n.) Look up bundling at Dictionary.com
1640s, "a gathering into a bundle," verbal noun from bundle (v.). Meaning "sharing a bed for the night, fully dressed, wrapped up with someone of the opposite sex" (1782) is a former local custom in New England (especially Connecticut and southeastern Massachusetts). It was noted there from about 1750s and often regarded by outsiders as grossly immoral, but New Englanders wrote defenses of it and claimed it was practiced elsewhere, too. It seems to have died out with the 18th century.
I am no advocate for temptation; yet must say, that bundling has prevailed 160 years in New England, and, I verily believe, with ten times more chastity than the sitting on a sofa. I had daughters, and speak from near forty years' experience. Bundling takes place only in cold seasons of the year--the sofa in summer is more dangerous than the bed in winter. [The Rev. Samuel Peters, "A general history of Connecticut," 1782]
bung (n.) Look up bung at Dictionary.com
mid-15c., "large stopper for a cask," from Middle Dutch bonge "stopper;" or perhaps from French bonde "bung, bunghole" (15c.), which may be of Germanic origin (or the Germanic words may be borrowed from Romanic), or it may be from Gaulish *bunda (compare Old Irish bonn, Gaelic bonn, Welsh bon "base, sole of the foot"). It is possible that either or both of these sources is ultimately from Latin puncta in the sense of "hole." Transferred to the cask-mouth itself (also bung-hole) from 1570s.
bung-hole (n.) Look up bung-hole at Dictionary.com
also bunghole, "hole in a cask for a stopper," 1570s, from bung (n.) + hole (n.). Sense extended to "anus" by c. 1600.
bungalow (n.) Look up bungalow at Dictionary.com
1670s, from Gujarati bangalo, from Hindi bangla "low, thatched house," literally "Bengalese," used elliptically for "house in the Bengal style" (see Bengal). Related: Bungaloid.