Etym: A term originating around Leeds for a sheep-sized creature, sometimes in the form of a dog, said to haunt people who would shortly die.
Padma Patil: Etym: In Sanskrit, means the lotus, the symbol of enlightenment, and has various related meanings. In present-day usage, also the main channel of the Ganges River.
Pansy Parkinson: Etym: Viola tricolor aka heartsease. Signifies "thoughts", and the common name is derived from the French for "thought".
paper airplanes (OotP ch. 7): Used for interoffice memos at the Ministry of Magic, as owls are too messy.
Paracelsus (PS ch. 6): The pseudonym of Philippus Aureolus Theophrastus Bombastus von Hohenheim (1493-1541), physician and alchemist, who established the role of chemistry in medicine, and was one of the first advocates of an empirical approach that became modern scientific method.
Parkinson, Pansy (PS ch. 7): A Slytherin in the same year as Harry; Draco's chief hanger-on and now his fellow prefect.
Etym: From a diminutive of Peter.
Parselmouth: One who has the automatic ability to speak Parseltongue.
Etym: According to Rowling, it's an old word for someone who has a mouth-related deformity.
Parseltongue: The language of snakes.
Partial Vanishment (OotP ch. 26): A weaker relative to Vanishing Spells.
Parvati Patil: Etym: EB: "The benevolent aspect of Shakti." Depending on which thread of Hinduism you follow, Shakti is either (a) the wife of Shiva, (b) a wife of Shiva, (c) the feminine, creative aspect of Shiva, (d) a personification of positive energy in general, or (e) all of the above but it doesn't matter since all definable things are illusion anyway.
Patil, Padma: A Ravenclaw, in the same year as Harry, now a prefect and a member of Dumbledore's Army.
Etym: See below.
Patil, Parvati: A Gryffindor, same year as Harry, and a member of Dumbledore's Army.
Etym: From the Pictish peit "portion (of land)" and Gaelic tulach "hill". Alternatively, also a surname of Indian origin.
Patricia Stimpson: Etym: Feminine form of Patrick.
Patrick Delaney-Podmore: Etym: The name of the patron saint of Ireland, whose original name was Sucat. This name comes from Latin patricius, "nobleman". Also a Scottish variant of partridge.
Patronus Charm: A spell that invokes a guardian spirit to protect the caster; the primary means of defense against dementors. An essential component of the spell is focusing on a happy thought-- the happier the thought, the stronger the Patronus. Incantation: Expecto Patronum.
Payne (GoF ch. 7): One of the campsite managers at the Quidditch World Cup.
Etym: From Latin pagus "outlying village", the same root as for pagan. At first it meant a rustic, then later a civilian, and finally a heathen.
Peasegood, Arnold (GoF ch. 7): An Obliviator who was at the Quidditch World Cup.
Etym: No info for this name. Pease is a variation of peas, meaning peas or the pea plant.
Peebles: A town on the England-Scotland border.
Peeves the Poltergeist: An obnoxious ghost inhabiting Hogwarts, teasing the students and irritating the staff and other ghosts. Controllable only by the teachers and the Bloody Baron.
Etym: Invented, as far as I can tell, from peeve.
Penelope Clearwater: Etym: The wife of Ulysses. When he was thought to be dead, she held off suitors by saying she must first finish weaving a shroud for Laertes. Each night, she would undo the weaving she had done that day, thus delaying them indefinitely. She has come to symbolize the chaste and faithful wife.
Pensieve: An invention of Dumbledore's which allows him to store and review memories.
Etym: Pun on pensive and sieve.
Pepper Imps: A magical candy which causes the eater to breathe smoke.
Peppermint Toad: A wizard candy.
Pepperup Potion: A concoction useful for perking up someone who is cold and damp.
Percival Wulfric Brian Dumbledore, Albus: Etym: A knight of the Round Table who entered Arthurian lore in the 12th century. The knightliest of the first group of knights.
Percy Ignatius Weasley: Etym: A family name that dates back to William de Perci, a comrade of William the Conqueror.
Perenelle Flamel: Etym: I seem to recall this is a name for some kind of flower, but can't find any info. Anyone?
Perkins (CoS ch. 3): Along with Arthur Weasley, the staff of the Misuse of Muggle Artifacts Office. The Weasleys borrowed a couple tents from him for the World Cup.
Etym: From another variation of Peter, from the Greek for "stone".
Perks, Sally-Anne (PS ch. 7): A student of unknown house, in the same year as Harry.
Etym: Variation of park, which in the Middle Ages meant a large enclosed area used for game hunting.
Permanent Sticking Charm (OotP ch. 5): What it sounds like. Used by Madam Black to ensure her picture would never be moved.
Peskipiski Pesternomi: An incantation that Lockhart claimed would drive off Cornish pixies.
Etym: At a guess, mangled English: pesky-piskey pester-no-me. Piskey is a dialectual variant of pixie.
Pest Advisory Bureau (OotP ch. 7): A section of the Ministry of Magic.
Peter Pettigrew: Etym: From the Greek petros "stone", a translation of the Aramaic Cephas.
Petrificatus Totalus: The incantation for the Body-Bind.
Etym: Latin-ish back-formation from petrify and total.
Pettigrew, Peter: One of James Potter's school friends, he became an Animagus with an animal form of a rat, which in retrospect really should have seen as some kind of warning. He later turned to the dark side and betrayed the Potters to Voldemort. When that unexpectedly resulted in Voldemort's fall, he faked his own death, cut off a finger to leave evidence framing Sirius Black for it, and took up a new life as Scabbers until Black hunted him down. Pettigrew then helped to resurrect Voldemort by cutting off an entire hand. One wonders what he's going to lose next time he switches sides.
Etym: From Old French petit "little" and cru "growth", a nickname for a small man, or an old form of "pedigree".
Petunia Evans Dursley: Etym: From petun, "tobacco"; the flower is in the tobacco family.
Philosopher's Stone: A substance representing the ideal combination of the essences of all elements, sought by alchemists down the ages, thought to make it possible to do all sorts of magical things. In these books, an actual stone which can be used to make the Elixir of Life.
Phineas Nigellus: Etym: From an Egyptian word meaning "black".
phoenix: A mythical bird which lives 500 years and then dies, only to be reborn in a magical fire. Rowling's variant symbolizes love or loyalty. Phoenix feathers are used as wand cores, and phoenix tears have healing powers.
Phyllida Spore: Etym: Probably from Greek phyllos, meaning "leaf".
Pierre Bonaccord: Etym: Same as below.
Piers Polkiss: Etym: A French variation of Peter.
Pigwidgeon: Ron's owl, given to him by Sirius Black and named by Ginny Weasley.
Etym: May be an alternate form of Pigwiggin, a fairy knight favored by Queen Mab, the wife of Oberon. Also, an archaic Scottish epithet.
Pince: The librarian at Hogwarts.
Etym: Variation of Pinch, a nickname for a chirpy person. Really.
Platform 9 3/4: The platform for the Hogwarts Express at King's Cross Station.
Pocket Sneakoscope: A magical device that spins and flashes when someone untrustworthy is present.
Podmore: see Delaney-Podmore.
Podmore, Sturgis (OotP ch. 3): A member of the Order of the Phoenix sent to Azkaban for trying to break into the Department of Mysteries.
Etym: See Delaney-Podmore.
Point Me: The incantation for the Four-Point Spell.
Poliakoff (GoF ch. 16): A student at Durmstrang.
Etym: Ethnic or regional name for someone from Poland.
Polkiss, Piers (PS ch. 2): Dudley Dursley's best friend and chief accomplice in tormenting Harry.
Etym: No etymology.
Polyjuice Potion: With the addition of a hair or other bit of someone, allows the drinker to take on the form of that person for one hour. Cannot be used for animal transformations.
pomegranate (OotP ch. 17): Its juice is not an ingredient in a Strengthening Solution.
Pomfrey, Poppy: The nurse at Hogwarts, for whom treating broken arms, catatonia, poison, and the like is a typical day's work.
Etym: Welsh name from the given name Humphrey, from the Germanic huun "bear cub" + frid "peace". (Alternately, OEW translates it as "peace through force".) St. Humphrey was a 9th century bishop of Therouanne.
Pontner, Roddy (GoF ch. 7): One of the people Ludo Bagman had bets on the Quidditch World Cup with.
Etym: Derived from Old French pont, "bridge".
Poppy Pomfrey: Etym: Various flowers of the genus Papaver. Signifies consolation or oblivion. Also, in the UK, worn to commemorate veterans of the World Wars.
porlock (OotP ch. 15): A creature the Care of Magical Creatures class was going to cover.
Porskoff Ploy: A Quidditch move in which a Chaser pretends to hold on to the Quaffle, drawing the opponents' attention, while actually passing it to someone else.
Etym: None found.
Portable Swamp (OotP ch. 29): A product of Weasley's Wizard Wheezes demonstrated during Hogwarts's revolt against Umbridge.
Portkey: An otherwise uninteresting object enchanted to transport anyone touching it to a predetermined location at a given time, or under specified circumstances.
Portkey Office (OotP ch. 7): An arm of the Ministry of Magic.
Portus (OotP ch. 36): The incantation that creates a Portkey.
Potions: A standard class at Hogwarts; taught by Professor Snape.
Potter, Harry: An orphaned wizard, unique among even his magically talented classmates in that dark forces really are constantly attacking him and causing him to miss class. Wand: 11", supple, holly and phoenix feather.
Etym: Stated by Rowling to be a name she just liked.
Potter, James: Harry's father, killed by Voldemort, but now wandering about as a shade. In school, he was a Gryffindor and became Head Boy. He was also an Animagus, taking on the form of a stag. Wand: 11", pliable, mahogany.
Potter, Lily Evans: Harry's mother, killed protecting Harry from Voldemort, now also resurrected as a shade. She came from a Muggle family, was a Gryffindor and became Head Girl when she was at Hogwarts. Wand: 10 1/4", swishy, willow.
Powers You Never Knew You Had and What to Do With Them Now You've Wised Up: A book in the Hogwarts library.
Practical Defensive Magic and Its Use Against the Dark Arts (OotP ch. 23): A set of books that Sirius and Lupin gave Harry for Christmas.
Prang, Ernie (PoA ch. 4): The driver of the Knight Bus.
Etym: Various meanings relating to crashing.
Predicting the Unpredictable: Insulating Yourself Against Shocks: A book in Flourish and Blotts.
prefect: A fifth-year or later student appointed by the teachers to take some responsibility for other students. There appears to be at least one prefect for each of the Hogwarts houses.
Prefects Who Gained Power: An engrossing book Percy picked up in Diagon Alley.
Prentice, Mr. (OotP ch. 21): One of Arabella Figg's cats.
Prewett, Fabian (OotP ch. 9): A member of the Order of the Phoenix who was killed by the Death Eaters.
Etym: Diminutive form of a name from Middle English prou(s) "brave", "valiant".
Prewett, Gideon (OotP ch. 9): A member of the Order of the Phoenix who was killed by the Death Eaters.
Etym: See above.
Pride of Portree (OotP ch. 25): A professional Quidditch team. Portree is a port on the Isle of Skye.
Pringle, Apollyon (GoF ch. 31): The caretaker who preceded Filch.
Etym: To have a prickly and tingling sensation. Also a proper surname.
Priori Incantatem: A phenomenon which occurs when two wands that share an identity are used in battle against each other. By this effect, Harry's wand caused Voldemort's to regurgitate the shades of its most recent victims.
Etym: Sort-of Latin, "former spell".
Prior Incantato: An incantation used on a wand to see what spell it was last used to cast.
Etym: See above.
Pritchard, Graham: A Slytherin, 3 years behind Harry.
Etym: As a surname, a Welsh patronymic derived from Richard, which may be from Middle English elements meaning "hard ruler". Pritch is also a mostly obsolete English word meaning "prod", "poke", or various sharp things.
Privet Drive: The street in Little Whinging where the Dursleys live. Privet is commonly used in hedges-- very much a feature of dull, conformist suburbia.
Prod, Warlock D. J., of Didsbury (CoS ch. 8): A satisfied Kwikspell customer.
Prongs: James Potter's nickname among his school buddies.
Protean Charm (OotP ch. 19): A spell that transfers changes in an object to linked copies of the object.
Etym: From Proteus, a prophet in Greek myth who was also regarded as a symbol of the original matter from which the universe was constructed.
Protego (OotP ch. 26): The incantation for the Shield Charm.
Etym: Latin, "I cover over, protect". Imperative: protege.
Pucey, Adrian (PS ch. 11): A Chaser for the Slytherin Quidditch team.
Etym: From a town in Berkshire.
Puddifoot, Madam (OotP ch. 25): The proprietor of a tea shop in Hogsmeade.
Etym: A name for someone compared in shape to a round barrel, from Middle English puddy "round-bellied" + fat "fat".
Puddlemere United: A Quidditch team which now includes Oliver Wood as a reserve player.
puffer fish: Any of the ninety or so fishes of the family Tetradontidae. Their eyes are an ingredient in a Swelling Solution.
puffskein (OotP ch. 6): There was a nest of dead ones under the sofa in the drawing room at the Black house.
Puking Pastilles (OotP ch. 6): Another component in a Skiving Snackbox. A pastille is a chewy, lozenge-shaped candy of sugar or sugar-covered fruit.
Pumpkin Pasties: A wizard candy, probably some kind of pastry with pumpkin filling.
pure-blood: Term for a wizard with no discernable Muggle or nonhuman ancestry. Used only by wizards who feel this sort of eugenic superiority gives them a divine right to rule others and operate outside the rules (as opposed to the actual divine right of Gryffindors to rule others and operate outside the rules).
Purge and Dowse Ltd. (OotP ch. 22): The storefront that hides St. Mungo's Hospital.
Etym: Purging (inducing vomiting) was one of the standard remedies, alongside bleeding, for just about anything before real medicine got going. Some dowsers, in addition to finding water, also claim the ability to locate sickness in the body.
Purkiss, Doris (OotP ch. 10): The witch who claimed in The Quibbler that Sirius Black was really Stubby Boardman.
Etym: From Anglo-Norman French purchacer "to acquire, buy", a name for an official who obtained supplies required by a manor house or monastery.
Put-Outer: A magical device that can supress lights.
Pye, Augustus (OotP ch. 22): The trainee Healer of the Dai Llewellyn Ward.
Etym: Various possible origins; I think the intended on is the Welsh patronymic derived from Hugh, which is from Old French hug "heart, mind, spirit".