Online Etymology Dictionary

builder (n.): late 13c., agent noun from build (v.).
building (n.): "a structure," c. 1300, verbal noun from build (v.).
built (adj.): 1560s, "constructed, erected," past participle adjective from build (v.). Meaning "physically well-developed" is by 1940s (well-built in reference to a woman is from 1871); Built-in (adj.) is from 1898.
bulb (n.): 1560s, "an onion," from Middle French bulbe (15c.), from Latin bulbus "bulb, bulbous root, onion," from Greek bolbos "plant with round swelling on underground stem." Expanded by 1800 to "swelling in a glass tube" (thermometer bulb, light bulb, etc.).
bulbous (adj.): 1570s, "pertaining to a bulb," from Latin bulbosus, from bulbus (see bulb). Meaning "bulb-shaped" is recorded from 1783. Related: Bulbously; bulbousness.
Bulgar (n.): 1759, "inhabitant of Bulgaria" (Bulgarian is attested from 1550s), from Medieval Latin Bulgarus (see Bulgaria).
Bulgaria (n.): Medieval Latin, from Bulgari "Bulgarians," perhaps literally "the men from the Bolg," the River Volga, upon whose banks they lived until 6c. But the people's name for themselves in Old Bulgarian was Blugarinu, according to OED, which suggests a different origin. In other sources [such as Room], the name is said to be ultimately from Turkic bulga "mixed," in reference to the nature of this people of Turko-Finnish extraction but Slavic language.
Bulgarian (n.): 1550s, from Bulgaria + -ian.
bulge (n.): c. 1200, "wallet, leather bag," from Old French bouge, boulge "wallet, pouch, leather bag," or directly from Latin bulga "leather sack" (see budget (n.)). Sense of "a swelling" is first recorded 1620s. Bilge (q.v.) might be a nautical variant.
bulge (v.): "to protrude, swell out," 1670s, from bulge (n.). Related: Bulged; bulging.
bulgur (n.): cereal food, from Turkish bulghur, bulgar.
bulimia (n.): 1976, Modern Latin, from Greek boulimia, "ravenous hunger" as a disease, literally "ox-hunger," from bou-, intensive prefix (originally from bous "ox;" see cow (n.)) + limos "hunger," from PIE root *leie- "to waste away." As a psychological disorder, technically bulemia nervosa. Englished bulimy was used from late 14c. in a medical sense of "ravishing hunger."
bulimic (adj.): 1854, "voracious;" see bulimia + -ic. Meaning "suffering from bulimia nervosa" is recorded from 1977. The noun in this sense is from 1980.
bulk (n.): mid-15c., "a heap," earlier "ship's cargo" (mid-14c.), from a Scandinavian source akin to Old Norse bulki "a heap; ship's cargo," thus "goods loaded loose" (perhaps literally "rolled-up load"), from Proto-Germanic *bul-, from PIE root *bhel- (2) "to blow, inflate, swell" (see bole).

Meaning extended by confusion with obsolete bouk "belly" (from Old English buc "body, belly," from Proto-Germanic *bukaz; see bucket), which led to sense of "size," first attested mid-15c.
bulk (v.): "swell, become more massive," 1550s (usually with up), from bulk (n.). Related: Bulked; bulking.
bulkhead (n.): late 15c., with head (n.); the first element perhaps from bulk "framework projecting in the front of a shop" (1580s), which is perhaps from Old Norse bolkr "beam, balk" (see balk (n.)).
bulky (adj.): mid-15c., "plump, stout," from bulk (n.) + -y (2). Related: Bulkiness.
bull (n.1): "bovine male animal," from Old English bula "a bull, a steer," or Old Norse boli "bull," both from Proto-Germanic *bullon- (source also of Middle Dutch bulle, Dutch bul, German Bulle), perhaps from a Germanic verbal stem meaning "to roar," which survives in some German dialects and perhaps in the first element of boulder (q.v.). The other possibility [Watkins] is that the Germanic root is from PIE *bhln-, from root *bhel- (2) "to blow, inflate, swell" (see bole).

An uncastrated male, reared for breeding, as opposed to a bullock or steer. Extended after 1610s to males of other large animals (elephant, alligator, whale, etc.). Stock market sense is from 1714 (see bear (n.)). Meaning "policeman" attested by 1859. Figurative phrase to take the bull by the horns first recorded 1711. To be a bull in a china shop, figurative of careless and inappropriate use of force, attested from 1812 and was the title of a popular humorous song in 1820s England. Bull-baiting attested from 1570s.
bull (n.2): "papal edict," c. 1300, from Medieval Latin bulla "sealed document" (source of Old French bulle, Italian bulla), originally the word for the seal itself, from Latin bulla "round swelling, knob," said ultimately to be from Gaulish, from PIE *beu-, a root supposed to have formed words associated with swelling (source also of Lithuanian bule "buttocks," Middle Dutch puyl "bag," also possibly Latin bucca "cheek").
bull (v.): "push through roughly," 1884, from bull (n.1). Related: Bulled; bulling.
bull (n.3): "false talk, fraud," Middle English, apparently from Old French bole "deception, trick, scheming, intrigue," and perhaps connected to modern Icelandic bull "nonsense."
Sais christ to ypocrites ... yee ar ... all ful with wickednes, tresun and bull. ["Cursor Mundi," early 14c.]
There also was a verb bull meaning "to mock, cheat," which dates from 1530s.
bull-dyke (n.): also bulldyke, 1926, from bull (n.1) + dyke.
bull-headed (adj.): also bullheaded, "obstinate," 1818, from bull (n.1) + head (n.).
bull-ring (n.): arena for bull fights, c. 1600, from bull (n.1) + ring (n.1).
bulla (n.): 1876, from Latin bulla (plural bullae), literally "bubble" (see bull (n.2)).
bulldog (n.): c. 1500, from bull (n.1) + dog (n.). Perhaps from shape, perhaps because originally used for baiting bulls.
bulldoze (v.): 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.): "person who intimidates by violence," 1876, agent noun from bulldoze (q.v.). Meaning extended to ground-clearing caterpillar tractor in 1930.
bullet (n.): 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.): 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.): 1560s, from bull (n.1) + finch; supposedly so called for the shape of its head and neck; compare French bouvreuil.
bullfrog (n.): also bull-frog, 1738, from bull (n.1) + frog (n.1). So called for its voice.
bullied (adj.): 1851, past participle adjective from bully (v.).
bullion (n.): 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.): 1560s, from bull (n.1) + -ish; stock market sense is from 1882. Related: Bullishly; bullishness.
bullock (n.): 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.): 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.): 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.): "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.): by 1942, from bullshit (n.). Related: Bullshitted; bullshitting.
bully (v.): 1710, from bully (n.). Related: Bullied; bullying.
bully (n.): 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.): 1904, coined by U.S. president Teddy Roosevelt, in reference to the White House.
bullying (n.): 1802, verbal noun from bully (v.).
bulrush (n.): 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.): "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;" see bole) + werc "work" (see work (n.)). Figurative sense "means of defense or security" is from 1570s.
bum (n.1): "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): "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.
bum (v.): 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.): "of poor quality," 1859, American English, from bum (n.). Bum steer in figurative sense of "bad advice" attested from 1901.