Baddock, Malcolm (GoF ch. 12): A Slytherin, three years behind Harry.
Etym: A diminutive of a Provençal name meaning "open-mouthed idiot".
Bagman, Ludo: A former Beater for the Wimbourne Wasps, a Death Eater allowed to remain free after pleading youthful misconduct, more recently the head of the Department of Magical Games and Sports, and most recently in hiding from goblin financiers who do not understand the term "debt restructuring".
Etym: The name means "one who carries a bag". In criminal jargon, can mean a money launderer, or someone who specializes in making inconvenienct people disappear.
Bagman, Otto (GoF ch. 5): Ludo Bagman's brother, who got into "a spot of trouble" with the Misuse of Muggle Artifacts Office over an enchanted lawnmower.
Bagshot, Bathilda (PS ch. 5): Author of A History of Magic.
Etym: A type of ammunition. Looking at this whole name, it appears the history of magic must have been pretty, um, exciting...
Ballycastle Bats: A British Quidditch team. Ballycastle may be a fictional place.
Bandon Banshee: Allegedly banished by Gilderoy Lockhart. A banshee is a wailing or singing demonic spirit; Bandon is a town in County Cork, Ireland.
Banishing Charm: The reverse of a Summoning Charm.
banshee: see Bandon Banshee.
Bane [Banes or Bain]:
Etym: Bunch of choices here: from a nickname meaning "bones"; a Welsh patronymic meaning "anvil"; Gaelic for "white, fair"; Middle English meaning "welcoming, friendly"; or Middle English/Old French meaning "bath". Or perhaps the character name is just from the modern English word.
Bartemius Crouch: Etym: From Aramaic Bartholomew "son of Tolmai". No etymology on Tolmai.
Baruffio (PS ch. 10): A wizard infamous for misspeaking a charm and conjuring up a buffalo.
Etym: No etymology.
Bashir, Ali (GoF ch. 7): A flying carpet merchant, upset that his wares are banned in Britain.
Etym: "Bringer of good news, messenger sent by Allah".
Basic Hexes for the Busy and Vexed: A book in the Hogwarts library.
Basil (GoF ch. 7): A wizard helping with logistics at the Quidditch World Cup.
Etym: From Greek basileios "kingly"; also the name for herbs of the genus Ocymum. There is a St. Basil, who was the bishop of Caesarea in the mid-4th century.
basilisk: A mythical creature supposed to spring from an egg laid by a rooster and incubated by a serpent or toad. Basilisks are usually depicted as snakelike, sometimes with a crown (its name derives from the Greek for "king") and are capable of turning any living thing to stone by looking at them.
The one which had been lurking in the Chamber of Secrets at Hogwarts is additionally in danger from the crowing of roosters, and generates an aura that sends spiders fleeing.
Bathilda Bagshot: Etym: OED has an entry for batilde, an obsolete form of a word meaning "embattled".
Bayliss, Hetty (CoS ch. 5): A Muggle who spotted the flying Ford Anglia.
Etym: From Late Latin baiulus "carrier, porter", cognate to bailiff.
Beater: A member of a Quidditch team who deflects Bludgers away from their teammates (and, ideally, toward the opponents).
Beauxbatons Academy: A school of wizardry which participates in the Triwizard Tournament; its current headmistress is Olympe Maxime. Its students speak with French accents, wear silk robes, and move in a balletic manner. (Ballet is absolutely essential to the British stereotype of the French.)
Etym: French, "lovely wands".
beechwood: Various trees of the genus Fagus, all tall, wide-spreading, and preferring temperate climes. The wood is durable under water, and used for cabinetry, tool handles, and shipping containers. Also cultivated as a shade tree.
Beginner's Guide to Transformation, A: The first-year textbook for Transfiguration.
Belch Powder: Something that can be gotten in Hogsmeade, probably from Zonko's Joke Shop.
Bell, Katie (PS ch. 12): A Chaser on the Gryffindor Quidditch team.
Etym: Does in fact come from Middle English for "bell".
belladonna: Atropa belladonna, deadly nightshade, the "essence" of which probably refers to atropine.
Bertha Jorkins: Etym: From Old English for "bright".
Bertie Bott's Every Flavor Beans: Jellybean-like magical candies of any flavor imaginable... including the ones you don't want to imagine.
bezoar: This term has been applied to various substances believed to be universal antidotes, but most commonly to a concretion formed around foreign matter in the gut of certain ruminants. Originally these were taken from the wild goat and antelope of Persia, which are also known as the bezoar goat and bezoar antelope.
bicorn: A creature from early French and English literature, it subsisted by devouring virtuous husbands. Powdered bicorn horn is one of the ingredients of the Polyjuice Potion.
Bilius (PoA ch. 6): One of Neville's uncles. He died a day after seeing a Grim.
Etym: Probably a variation of bilious.
Bill Weasley [William]:
Etym: From Old German vilja "will" + helma "helmet".
Binky (PoA ch. 8): Lavender Brown's rabbit, killed by a fox.
Binns, (first name unknown): The teacher of the History of Magic classes at Hogwarts, and unusual among history teachers for being as dead as his lectures.
Etym: From the Old English name Binna, of uncertain origin, or a word for an open manger, stall, or hollow place.
Black Forest: An area in Germany.
Black, Sirius: Harry's godfather, one of James Potter's school friends, imprisoned in Azkaban for killing Peter Pettigrew and twelve Muggles, now escaped and on the run until such time as the authorities can be presented with sufficient evidence that Pettigrew is in fact alive and responsible for the murders. Sirius is also an unregistered Animagus, taking the form of a large black dog.
Etym: Just means black. As a side note, though, some instances of this surname come from Old English blac, the equivalent of French blanc... meaning "white"!
Black Malfoy, Narcissa: Etym: See below.
bladvak: The Gobbledygook word for "pickax".
Blaise Zabini: Etym: Full etymology unknown but cognate to Blasius, the name of the patron saint of wool-workers and sufferers of throat diseases. Once very popular in England, a major wool producer. ECN: "The only relic of the trade in Romsey, Hants (once a wool staple), is an inn called the Bishop Blaise."
Blast-Ended Skrewts: A cross between fire-crabs and manticores used by Hagrid for the Care of Magical Creatures class.
Bletchley (PS ch. 11): The Keeper for the Slytherin Quidditch team in Harry's first year.
Blood-Sucking Bugbear: What Hagrid thought might be killing his roosters. A bugbear in popular legend is a monster in the shape of bear said to devour naughty children.
Bloody Baron: The house ghost of Slytherin.
Bludger: A small, hard ball used in Quidditch. Bludgers fly around the field of play attempting to knock players off their brooms.
Etym: Undoubtedly from bludgeon. OED has an entry for bludger, actually, but in the interest of preserving our G rating we must move on.
bluebell fire: A magically conjured blue fire that can be carried around in a jar.
Bluebottle: A type of flying broom, advertised as "A Broom for the Whole Family."
Bode (GoF ch. 7): An Unspeakable who was at the Quidditch World Cup.
Etym: From the Germanic word "to announce", meaning much the same as the English word bode.
Body-Bind: A curse that paralyzes the target completely. Incantation: Petrificatus Totalus.
Bodrod the Bearded (GoF ch. 31): May have been a participant in a historical goblin rebellion.
Etym: No info; probably invented.
boggart: In these books, a creature that assumes the appearance of whatever a person looking at it fears most. Can be banished with a humorous mental image and the incantation Riddikulus.
Bole (PoA ch. 15): A Beater on the Slytherin Quidditch team.
Etym: Something of a cylindrical shape, such as the trunk of a tree or a pillar. As a name, an anglicized form of Ó Baoighill, possibly from words meaning "rash pledge", or derived from the placename Boyville.
Bones, (first names unknown) (PS ch. 4): The last name of a wizard couple killed by Voldemort.
Etym: Derived via Yiddish from Italian bona "good".
Bones, Susan (PS ch. 7): A Hufflepuff, in the same year as Harry.
Etym: See above.
Bonfire Night: November 5th, in England the commemoration of the Gunpowder Plot. Typically involves lots of fireworks.
boomslang: Dispholidus typus.
Boot, Terry (PS ch. 8): A Ravenclaw, the same year as Harry, and a member of Dumbledore's Army.
Etym: From Middle English for "boot" or Dutch for "boat".
Borgin and Burkes: A shop in Knockturn Alley specializing in the ingredients of dark magic; Evil backwards-R Us.
Etym: No info on Borgin, but perhaps it's supposed to sound like Borgia. The name Burke comes from Old High German burg "fortification". A likelier source for the store's name, however, is the 19th-century murderer and grave-robber William Burke.
Borgin, Mr. (CoS ch. 4): One of the founders of Borgin and Burkes, still working there, or else a descendant.
Etym: See above.
Boris the Bewildered (GoF ch. 23): A statue of him is near the prefects' bathroom.
Etym: Russian name of uncertain etymology; may signify "fight".
bouillabaisse: A fish stew whose characteristic form originated in France.
Bouncing Bulbs: Some sort of plant covered in the Herbology class.
Bozo (GoF ch. 24): Rita Skeeter's photographer.
Branstone, Eleanor (GoF ch. 12): A Hufflepuff, three years behind Harry.
Etym: From the Old English name Brant + tuun "enclosure, settlement".
Break with a Banshee: One of Gilderoy Lockhart's books.
Brockelhurst, Mandy (PS ch. 8): A Ravenclaw, the same year as Harry.
Etym: Placename, after a wooded hill that was home to badgers. Brock on its own has been a word for various small animals, including badgers.
Broken Balls: When Fortunes Turn Foul: A book on divination at Flourish and Blotts.
brooms: The flying broom is an ancient and venerable mode of wizard transportation, and an indispensable part of Quidditch. Types of brooms include the Bluebottle, Cleansweep Five, Cleansweep Seven, Comet Two Sixty, Firebolt, Nimbus Two Thousand, Nimbus Two Thousand and One, Silver Arrow, and Shooting Star.
Brown, Lavender (PS ch. 8): A Gryffindor, the same year as Harry.
Etym: Really means "brown".
brown owl: A very common European owl, known most commonly as the tawny owl.
Bryce, Frank: The gardener at the Riddle House, killed by Voldemort, brought back as a shade.
Etym: No etymology; suspected to be of Celtic origin.
Bubotuber: A magical plant useful for making an acne remedy.
Etym: Bubo as in bubonic plague; there is a plant structure called a bulbo-tuber, which is neither a true bulb nor a true tuber.
Buckbeak: A hippogriff falsely accused of being dangerous, now on the run with Sirius Black.
Etym: Probably invented.
budgie: A small yellow bird, very popular as a pet in Britain at one time, less common these days.
bugbear: see Blood-Sucking Bugbear.
Bulstrode, Millicent (PS ch. 8): A Slytherin, the same year as Harry.
Etym: A place name, from Old English burh "fortress, town" or bula "bull" + strood "brushwood".
Burning Day: The day on which a phoenix renews itself.
Burrow, The: The house of the Weasley family.
butterbeer: A popular drink at the Three Broomsticks, nonintoxicating to humans, but with a strong effect on house-elves.