英语词源字典 - 在线词源网站

Bacardi [Bacardi 词源字典]: 1921, name for a brand of West Indian rum produced by Compania Ron Bacardi, originally of Cuba.[Bacardi etymology, Bacardi origin, 英语词源]
baccalaureate (n.): 1620s, "university degree of a bachelor," from Modern Latin baccalaureatus, from baccalaureus "student with the first degree," alteration of Medieval Latin baccalarius "one who has attained the lowest degree in a university, advanced student lecturing under his master's supervision but not yet having personal license" (altered by folk etymology or word-play, as if from bacca lauri "laurel berry," laurels being awarded for academic success).

The Medieval Latin word is of uncertain origin; perhaps ultimately from Latin baculum "staff" (see bacillus), which the young student might carry. Or it might be a re-Latinization of bachelor in its academic sense.

In modern U.S. usage, baccalaureate usually is short for baccalaureate sermon (1864), a religious farewell address to a graduating class at an American college, from the adjectival sense "pertaining to the university degree of bachelor."
baccarat (n.): card game, 1848, from French baccara (19c.), which is of unknown origin. Baccarat is the name of a town in France that was noted for glass-making.
Bacchae (n.): "female attendants of Bacchus," from Greek Bakkhai, plural of Bakkhe, from Bakkhos (see Bacchus).
bacchanal: 1530s (n.); 1540s (adj.), from Latin bacchanalis "having to do with Bacchus" (see Bacchus). Meaning "riotous, drunken roistering; orgy" is from 1711.
bacchanalia (n.): "drunken revelry," 1630s, from the name of the Roman festival held in honor of Bacchus, from neuter plural of Latin bacchanalis (see bacchanal). A participant is a Bacchant (1690s), fem. Bacchante, from French. The plural of both is Bacchantes.
bacchanalian (adj.): 1560s; see bacchanalia + -an. As a noun from 1610s.
Bacchus: Greek god of wine and revelry, a later name of Dionysus, late 15c., from Latin Bacchus, from Greek Bakkhos, perhaps related to Latin bacca "berry, olive-berry, bead, pearl." Perhaps originally a Thracian fertility god.
bach (n.): 1845, American English, clipped form of bachelor (n.). Also in colloquial American English use as a verb (1870) meaning "to live as an unmarried man," especially "to do one's own cooking and cleaning." Related: Bached; baching.
bachelor (n.): c. 1300, "young man;" also "youthful knight, novice in arms," from Old French bacheler, bachelor, bachelier (11c.) "knight bachelor," a young squire in training for knighthood, also "young man; unmarried man," and as a university title, of uncertain origin, perhaps from Medieval Latin baccalarius "vassal farmer, adult serf without a landholding," one who helps or tends a baccalaria "field or land in the lord's demesne" (according to old French sources, perhaps from an alteration of vacca "a cow" and originally "grazing land" [Kitchin]). Or from Latin baculum "a stick," because the squire would practice with a staff, not a sword. "Perhaps several independent words have become confused in form" [Century Dictionary]. Meaning in English expanded early 14c. to "young unmarried man," late 14c. to "one who has taken the lowest degree in a university." Bachelor party as a pre-wedding ritual is from 1882.
bachelorette (n.): 1935, American English, from bachelor with French ending -ette. Replaced earlier bachelor-girl (1895). Middle French had bachelette "young girl;" Modern French bachelière is found only in the "student" sense.
bacilli (n.): plural of bacillus (q.v.).
bacillus (n.): 1877, medical Latin, from Late Latin bacillus "wand," literally "little staff," diminutive of baculum "a stick," from PIE root *bak- "staff" (also source of Greek bakterion; see bacteria) + instrumentive suffix -culo. Introduced as a term in bacteriology 1853 by German botanist Ferdinand Cohn (1828-1898).
back (n.): Old English bæc "back," from Proto-Germanic *bakam (cognates: Old Saxon and Middle Dutch bak, Old Frisian bek), with no known connections outside Germanic. In other modern Germanic languages the cognates mostly have been ousted in this sense ib words akin to Modern English ridge (cognates: Danish ryg, German Rücken). Many Indo-European languages show signs of once having distinguished the horizontal back of an animal (or a mountain range) from the upright back of a human. In other cases, a modern word for "back" may come from a word related to "spine" (Italian schiena, Russian spina) or "shoulder, shoulder blade" (Spanish espalda, Polish plecy).

To turn (one's) back on (someone or something) "ignore" is from early 14c. Behind (someone's) back "clandestinely" is from late 14c. To know (something) like the back of one's hand, implying familiarity, is first attested 1893. The first attested use of the phrase is from a dismissive speech made to a character in Robert Louis Stevenson's "Catriona":
If I durst speak to herself, you may be certain I would never dream of trusting it to you; because I know you like the back of my hand, and all your blustering talk is that much wind to me.
The story, a sequel to "Kidnapped," has a Scottish setting and context, and the back of my hand to you was noted in the late 19th century as a Scottish expression meaning "I will have nothing to do with you" [see Longmuir's edition of Jamieson's Scottish dictionary]. In English generally, the back of (one's) hand has been used to imply contempt and rejection since at least 1300. Perhaps the connection of a menacing dismissal is what made Stevenson choose that particular anatomical reference.
back (v.): late 15c., "to move (something) back," from back (adv.). Meaning "to support" (as by a bet) is first attested 1540s. Related: Backed; backing.
back (adj.): Middle English, from back (n.) and back (adv.). Formerly with comparative backer (c. 1400), also backermore. To be on the back burner in the figurative sense is from 1960, from the image of a cook keeping a pot there to simmer while he or she works on another concoction at the front of the stove.
back (adv.): late 14c., shortened from abak, from Old English on bæc "backwards, behind, aback" (see back (n.)). Adverbial phrase back and forth attested from 1814.
back down (v.): in figurative sense of "withdraw a charge," 1859, American English, from notion of descending a ladder, etc.; from back (v.) + down (adv.).
back off (v.): "retreat, stop annoying someone," by 1938, from the verbal phrase, from back (v.) + off (adv.).
back seat (n.): also back-seat, 1832, originally of coaches, from back (adj.) + seat (n.). Used figuratively for "less or least prominent position" by 1868. Back-seat driver first attested 1926.