From Harry Potter and the Sorcerer's Stone, Harry Potter and the Chamber of Secrets, Harry Potter and the Prisoner of Azkaban, and Harry Potter and the Goblet of Fire by J.K. Rowling. 

Aconite - Plant used in potions. Also known as monkshood or wolfbane. 

Alchemy - Medieval science that was founded on the search to turn metal into gold. 

Arithmancy - ancient study of the magical properties of numbers. 

Bezoar - Stone taken from the stomach of a goat. Will counteract most poisons. 

Blast-Ended Skrewts - They smell like rotten fish and look like deformed shell-less lobsters, pale and slimy looking with no heads. The legs, about six inches long, stick out in odd places. They are propelled by sparks that come out of an end, which causes the skrewts to blast off. The females suck blood; the males sting.(vol.4, p. 196-197) 

Bludgers - Black balls that try and knock players off their brooms in Quidditch. 

Broomstick Servicing Kit - A black leather case containing Fleetwood's High Finish Handle Polish, tail- twig clippers, compass, and a Do-it-Yourself Broomcare Handbook. A 13th birthday present for Harry from Hermoine. 

Bubotubers - Ugly plants that look like thick, black, giant slugs, which when squeezed emit a valuable pus, used in the treatment of acne. p. 194-195. 

Charm - Spell that adds properties to an object or person. 

Cobbing - Excessive use of elbows - cause for a penalty in Quidditch. 

Common Welsh Green - Type of dragon found in Britain. 

Cornish Pixies - Naughty little fairies that create havoc. 

Counter Curse - Used to remand a curse. (vol. 2, p. 13) 

Daily Prophet - The Wizard newspaper. 

Dark Creatures - Boggarts, Red Caps, hinkypunks, grindylows, Kapas, and werewolves. (vol. 4, p. 211) 

Dark Mark - A colossal skull, comprised of emerald stars, with the serpent protruding from its mouth like a tongue. You-Know-Who's sign that was spotted in the sky during the Quidditch Cup. 

Deathday Party - A celebration held by Nearly Headless Nick, to commemorate the day he died, to which Harry and his friends are invited. (vol. 2, p. 130) 

Defense Against the Dark Arts - Magic lessons at Hogwarts that teach students how to defend themselves against evil creatures. 

Deflating Draft - Potion that counteracts a swelling solution. Causes swollen body parts to return to normal size. 

Dementor's Kiss - What dementors use when they want to utterly destroy someone; they clamp their jaws upon the mouth of their victim, and suck out their soul. The victim is left with no sense of self, no memory. They are empty shells. This was to be performed on Sirius Black, as ordered by the Ministry of Magic. (vol. 3, p. 247) 

Devil's Snare - A plant with strong, snake-like tendrils that likes the dark and damp, and is weakened by light and warmth. (vol. 1, p. 277) 

Divination - Magical art of telling the future. 

Draco dormiens nunquam titillandus - The Hogwarts motto: Never tickle a sleeping dragon. 

Dragon - Mythical reptilian creature that can fly and breathe fire. 

Draught of the living death - Powerful sleeping potion. 

Elixir of Life - Potion produced by the Philosopher's (Sorcerer's) Stone that will make the drinker immortal. 

Exams - O.W.L.s, Ordinary Wizardry levels; N.E.W.T.s, Nastily Exhausting Wizarding Tests (highest qualification Hogwart's offers). 

Fidelius Charm - A complex spell involving the magical concealment of a secret inside a living soul. The secret is safe unless the secret keeper decides to reveal it. (vol. 3, p. 205) 

Firebolt - Fastest most technologically advanced, broomstick. Can accelerate from 0-150 miles per hour in ten seconds. 

Flobberworm - Species of worm that Harry and his friends have to keep alive to pass the Care of Magical Creatures course. 

Floo Powder - A glittery powder used to help witches travel from one place to another. Throw it into the fire, say the name of your destination, and step into the flames. 

Ford Anglia - The make of Mr. Wesley's enchanted car. 

Gnomes - Very small creatures that live in holes in gardens. They have leathery skin and large bald heads. To de-gnome a garden, grab the gnome by the ankles and swing it around your head, and then throw. 

Goblet of Fire - A large rough-hewn wooden cup, filled to the brim with dancing blue-white flames into which aspiring champions can drop their names, if they want to participate in the Triwizard Tournament. (vol. 4, p. 256-257) The goblet will return the names of three deemed most worthy to represent their schools. Placed on the stool that normally held the Sorting Hat. (Vol. 4, p.259) 

Gobstones - The wizarding version of marbles. They squirt a stinky substance into players' faces when they lose a point. 

Golden Snitch - Small golden ball with silver wings used in Quidditch. Must be caught by seeker in order to end the match. 

Gregory the Smarmy - Statue at Hogwarts. 

Grim - A giant black dog taken to be a death omen. 

Grindylow - Water demon. Sickly green with sharp horns and very long fingers. 

Hebridean Black - A breed of wild dragon found in Britain. 

Herbology - Study of plants. Professor Sprout is the teacher. 

Hinkypink - Small creatures that live in bogs and swamps. They wander about at night with lanterns to lure lost travelers into the swamps. 

Hogwart Banners - Red with gold lion -Gryffindor; blue with bronze eagle- Ravenclaw; yellow with black badger-Hufflepuff; green with silver serpent- Slytherin. (vol. 4, p.237) 

Hogwarts Coat of Arms - lion, eagle, badger, and snake united around a large letter "H." (vol. 4, p.237) 

Howler - A letter, in a red envelope, when opened emits an explosive roar of sound. The voice of the person who sent it can be heard piercing the air. Usually sent by parents when they have a complaint to their children. After delivery of a Howler, the red envelope bursts into flames. (vol. 2, p. 87) 

Invisibility Cloak - Long and silvery; Harry inherited it from his dad. 

Kappa - Monkey-like creatures that live in water and strangle people who invade their territory. 

Keeper - Quidditch player who guards the goal posts. 

Kwikspell - A correspondence course in beginner's magic. (vol. 2, p. 127) 

Magic Incantations - Expelliarmus; Rictusempra; Tarantallegra; Serpentsortia, etc. Also see Spells and Charms section 

Mandrake Restorative Draught - Used to de-petrify Mrs. Norris. 

The Marauder's Map - Showed every detail of the Hogwart's castle and its grounds. To get the map to work, one has to say "I solemnly swear that I am up to no good." When you touch the wand lightly and say, "Mischief managed," it will go blank. (vol. 3, p. 193)

Mirror of Erised - Enables one to see what they most want to see - "The most desparate desire of my heart." Erised is desire spelled backward. (For Harry, it is his dead parents.) (vol. 1, p. 209)

Monkshood - Plant used in potions. Also known as aconite or wolfsbane. 

Monster Book of Monsters - Large green book of monsters. Required reading for third years. Must be stroked down the spine or it will bite your fingers. 

Mudblood - Term used to describe a person of non-magic parents. Considered to be a great insult. 

Muggle Studies - Class taken by wizarding folk to study non-magical people. 

N.E.W.T.'s - Nastily Exhausting Wizarding Tests. Higher level examinations at Hogwarts. 

Nimbus 2000 - Type of broomstick. Harry's first broomstick. 

Nimbus 2001 - The successor to the Nimbus 2000. 

Norwegian Ridgeback - Breed of dragon that is very rare. Hagrid had one as a pet. 

O.W.L.'s - Ordinary Wizarding levels. The standard-level examinations at Hogwarts. (vol. 1, p. 55) 

Parselmouth - One who can talk to snakes.

Parseltongue - A language spoken by a Parselmouth. 

Philosopher's (Sorcerer's) Stone - Legendary stone which will transform any metal into pure gold. It also produces The Elixir of Life, which makes the drinker immortal. The only known stone belongs to Nicholas Flamel, Albus Dumbledore's partner. 

Pocket Sneakoscope - Lights up and spins if someone untrustworthy is around. 

Pointed Hat - Part of uniform at Hogwarts. 

Put-Outer - Device resembling a cigarette lighter, used to turn street-lamps on and off. Used by Albus Dumbledore. 

Quaffle - Red ball used for scoring in Quidditch. 

Quidditch - Wizard sport similar to soccer, but played in the air on broomsticks. Seven players on each team; three of them called chasers; uses three different balls - a Quaffle, red soccer sized ball; two bludger balls (black); the Golden Snitch - a tiny, winged, walnut-sized ball that the Seeker has to catch. Points are earned each time the ball goes through the hoop; the catching of the Golden Snitch signals the end of a game. (vol. 1, p. 167, also,vol. 3, p. 143) 

Quidditch Brooms - Nimbus 2000, Cleansweep Seven, Comet 260, Nimbus 2001, - light, speedy first-class Quidditch brooms. (vol. 1, p. 152) Firebolt - The most magnificent broom Harry had ever seen; the fastest broom in the world. (vol. 3, p. 57 & p. 254) A gift from Sirius. (vol. 3, p. 432) 

Quidditch Plays - Wronski Defensive Feint; Dangerous Seeker Diversion; Hawkshead Attacking Formation; Porskoff Ploy. Plays used during Quidditch World Cup. (vol. 4, pp.106 &109) 

Red Cap - Goblin-like creature found in places where bloodshed has occurred. They lie in wait to bludgeon the lost. 

Remembrall - A glass ball the size of a large marble which is filled with white smoke. The smoke turns red to tell you that there is something you forgot to do. (vol. 1, p. 145) 

Self-shuffling playing cards - Wizarding playing cards which shuffle themselves. 

Sickle - Silver wizarding money. 

Skele-gro - Potion used to re-grow bones. 

Sorcerer's Stone - More than 600 years old. Can transform any metal into pure gold; it also produces the elixer of Life which makes the drinker immortal. (vol. 1, p. 220) 

Sorting Hat - A patched frayed, dirty, pointed wizard's hat used to determine which house a Hogwart's student will be in. When not in use the hat sits on a four-legged stool. 

Spellotape - Wizarding repair tape. It was used by Ron Weasley to mend his broken wand. 

S.P.E.W. - Society for the Promotion of Elfish Welfare. A movement begun by Hermione to improve the lives of House-elves. (vol. 4, p. 224) Squib - Someone born into a wizarding family but without any magical powers (Argus Fitch). (vol. 2, p. 142) 

Swelling Solution - Potion that causes body parts to swell to enormous proportions. 

Time-turner - Hourglass necklace that Hermione wears to take her back in time, in order to rescue sirius Black (vol. 3, p. 395) 

Toothflossing Stringmints - Wizarding sweets that floss your teeth while you suck them. 

Transfiguration - The art of turning one thing into another. 

Transfiguration Today - Wizarding magazine about transfiguration. 

Trevor - Name of Neville Longbottom's pet toad. 

Unicorn - Mythical white horse-like creature with golden mane and a golden horn sprouting from its head. Innocent, beautiful creature, Tail hair and horn can be used in magic. Dark wizards have been known to kill unicorns and drink their blood, which will sustain the life of the drinker. 

Unicorn Blood - Silver in color. Possesses magical and ominous qualities. (vol 1, p. 250) 

Vampire - Evil creature that roams the night feeding on the blood of living beings. Cannot go out in the daylight. 

Wand - Implement used by wizards for magic. Available from Ollivanders in Daigon Alley. 

Werewolf - Half-man, half-wolf creature. A werewolf will kill given the chance. If not fatal, the werewolf's bite will turn the victim into a werewolf, too. 

Which Broomstick?- Broomstick consumer magazine. Test-rides all makes of brooms and reviews them. 

Whomping Willow - A large, very violent tree in the Forbidden Forest, on the grounds of Hogwarts, that hits anything that comes too close to it. 

Wizard Money - Galleon (gold), Sickle (silver) Knut and Lapin (bronze). 

Wingardium Leviosa - Magic incantation to get an object to fly. (vol. 1, p. 171) 

Wizard Crackers - Party favors that blast like cannons and produce clouds of smoke.