Babbling Curse: Details unknown; Lockhart claimed to have cured a Transylvanian villager of it.
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.
Bagnold, Millicent (OotP ch. 5): Fudge's predecessor as Minister of Magic.
Etym: From Old English beadu "battle" + halh "nook, recess" or holt "wood".
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.
Barnabas Cuffe: Etym: See below.
Barnabas the Barmy (OotP ch. 18): A wizard who attempted to train trolls to do ballet, commemorated in a tapestry opposite the Room of Requirement.
Etym: From bar "son" and Nabia, a name maybe meaning "confession". The name of a biblical missionary.
Barnsley (OotP ch. 1): An industrial town in Yorkshire (for the British perception of it, read "dour and boring"), location of the Five Feathers.
Barry Ryan: Etym: From Irish bearrach "spear".
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.
Baruffio's Brain Elixir (OotP ch. 31): Confiscated by Hermione from Eddie Carmichael.
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.
Bat-Bogey Hex (OotP ch. 6): A spell that summons winged imps to harass the target. A specialty of Ginny Weasley's.
Etym: Bogey or bogy is a term covering many different malicious folkloric spirits.
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.
Beast Division (OotP ch. 7): A section of the Ministry of Magic for dealing with magical creatures.
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.
Befuddlement Draught (OotP ch. 18): A potion that creates hot-headedness or recklessness.
Beginner's Guide to Transformation, A: The first-year textbook for Transfiguration.
Being Division (OotP ch. 7): A section of the Ministry of Magic for dealing with magical sentients.
Belby, Marcus (HBP ch. 7): A member of the Slug Club because of his uncle Damocles. One year ahead of Harry.
Etym: Couldn't find anything.
Belcher, Humphrey (HBP ch. 10): According to Dumbledore, the man who believed the time was right for a cheese cauldron.
Etym: From Old French bel "lovely" + chere "face, countenance", or a variation on a name meaning "beam". Also the last name of a caricaturist for Punch.
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, and a member of Dumbledore's Army.
Etym: Does in fact come from Middle English for "bell".
belladonna: Atropa belladonna, deadly nightshade, the "essence" of which probably refers to atropine.
Bellatrix Black Lestrange: Etym: The name of a star; the name also means "female warrior".
Etym: Literally, Hebrew for "son of the south", interpreted as "son of the right hand". Allusively, the favored son or the best share.
Benson, Amy (HBP ch. 13): A child in the same orphanage as Tom Riddle, somehow harmed by him.
Etym: Patronymic deriving from Benedict "blessing", or from an Old English placename meaning "Banesa's settlement".
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.
Etym: From Old German words berhta "bright" + hraben "raven"; the name of the family in Mansfield Park, which also gave us Mrs. Norris.
Bertram Aubrey: Etym: See above.
Bethnal Green (OotP ch. 7): An area of London, the site of the third regurgitating toilet incident.
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.
Etym: From Old German vilja "will" + helma "helmet".
Etym: See above.
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.
Bishop, Dennis (HBP ch. 13): Another of Tom Riddle's fellow orphans, which he did something to.
Etym: Means what it looks like.
Black Forest: An area in Germany.
Black(?), Alphard (OotP ch. 6): Sirius's uncle, estranged from the family for supporting him.
Etym: See below.
Black(?), Elladora (OotP ch. 6): Sirius's aunt, who started the family tradition of beheading elderly house-elves.
Etym: See below.
Black Lestrange, Bellatrix: Etym: See below.
Black, Madam (OotP ch. 4): Sirius's mother, technically dead but still very much a presence through her portrait.
Etym: See below.
Black Malfoy, Narcissa: Etym: See below.
Black, Regulus (OotP ch. 6): Sirius's younger brother, a Death Eater during the first wizard war and not terribly good at it either.
Etym: See below.
Black, Sirius: Harry's godfather and a member of the Order of the Phoenix, imprisoned in Azkaban for years after being framed by Peter Pettigrew, and now unfortunately and rather confusingly dead.
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 Tonks, Andromeda: Etym: See above.
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.
Blaze Box (OotP ch. 28): A unit of Weasleys' Wildfire Whiz-Bangs.
Bletchley, Miles (PS ch. 11): The Keeper for the Slytherin Quidditch team in Harry's first year.
Blibbering Humdinger (OotP ch. 13): Another creature only {The Quibbler believes in.
Blood Blisterpod (OotP ch. 14): One of the components of the Skiving Snackbox.
Blood Brothers: My Life Amongst the Vampires (HBP ch. 15): Eldred Worple's account of vampire life.
Blood-Replenishing Potion (OotP ch. 22): A treatment for hemorrhages at St. Mungo's Hospital, apparently obviating the need for transfusions.
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."
Boardman, Stubby (OotP ch. 10): According to the The Quibbler, Sirius Black's real name, under which he was the lead singer of The Hobgoblins.
Etym: Originally a name for a person who lived on the edge of a town, from Middle English border "edge".
Etym: See Roberts.
Bobbin, Melinda (HBP ch. 11): A student at Hogwarts whose family owns a large chain of apothecaries.
Etym: A spool of thread, or a small bundle of wood.
Bode, Broderick (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.
Bonaccord, Pierre (OotP ch. 31): The first Supreme Mugwump of the International Confederation of Wizards.
Etym: French, "good agreement".
Bonder (HBP ch. 2): The caster of the spell cementing an Unbreakable Vow.
Bones, Amelia Susan (OotP ch. 7): An official at the Wizengamot, killed by the Death Eaters.
Etym: Derived via Yiddish from Italian bona "good".
Bones, Edgar (OotP ch. 9): A member of the Order of the Phoenix who was killed by the Death Eaters along with other members of his family.
Etym: See above.
Bones, Susan (PS ch. 7): A Hufflepuff, in the same year as Harry, and a member of Dumbledore's Army.
Etym: See above.
Bonfire Night: November 5th, in England the commemoration of the Gunpowder Plot. Typically involves lots of fireworks.
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".
Borage, Libatius (HBP ch. 9): Author of Advanced Potion-Making.
Etym: A group of plants in the genus Boraginaceae. The main British species is used to make cordial, and as a flavoring for alcoholic drinks.
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.
bowtruckle (OotP ch. 13): Twig-like creatures that guard trees with wand-quality wood.
Etym: Possibly bow as in "bend" + the obsolete word truckle "be subservient, yield, be daunted".
Bozo (GoF ch. 24): Rita Skeeter's photographer.
Bradley (OotP ch. 31): A Chaser on the Ravenclaw Quidditch team.
Etym: Possibly after Francis Herbert Bradley, an idealist philosopher.
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.
Brian Dumbledore, Albus Percival Wulfric: Etym: Brian Boru, the legendary high king of Ireland.
Bring-and-Fly Sale (OotP ch. 15): The wizard variant of a "Bring and Buy Sale", a sort of community flea market organized in aid of a church, school, or community center.
British and Irish Quidditch League (OotP ch. 7): The league in which the professional Quidditch teams listed here play; its headquarters are at the Ministry of Magic.
Brockdale Bridge (HBP ch. 1): A bridge which collapsed unexpectedly, killing an unreported number of Muggles.
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.
Broderick Bode: Etym: None found.
Broken Balls: When Fortunes Turn Foul: A book on divination at Flourish and Blotts.
Brookstanton, Rupert "Axebanger" (HBP ch. 30): A former Hogwarts student.
Etym: I was able to find that Stanton from Old English staan "stone" + tuun "enclosure".
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, Cleansweep Six, Comet Two Ninety, Comet Two Sixty, Firebolt, Nimbus Two Thousand, Nimbus Two Thousand and One, Silver Arrow, and Shooting Star.
Broom Compass (OotP ch. 23): Presumably a compass that can be mounted on a broom.
Broom Regulatory Control (OotP ch. 7): An arm of the Ministry of Magic.
Brown, Lavender (PS ch. 8): A Gryffindor, the same year as Harry, a founding member of Dumbledore's Army.
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.
Budleigh Babberton (HBP ch. 4): Horace Slughorn's last hiding place before he was lured back to Hogwarts.
Etym: There is no such place, although there is a Budleigh Salterton.
bugbear: see Blood-Sucking Bugbear.
Bulbadox Powder (OotP ch. 12): A powder that causes boils.
Etym: From Latin roots meaning "rounded object" and "inflate".
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".
Bungs, Rosalind Antigone (HBP ch. 30): A former Hogwarts student.
Etym: A bung can be a stopper, or the mouth of a cask, or a brewer, pickpocket, or lie. Circa 1900, it was also slang for a bribe.
Bungy (OotP ch. 1): A budgie who lives at the Five Feathers who has learned to water-ski.
Burke, Caractacus: One of the founders of Borgin and Burkes.
Etym: See under Borgin and Burkes.
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.