Accio! (Goblet of Fire, page 68)
Latin Root: accedo (to approach, come near / (things) to be added)
The Summoning Charm (incantation: "Accio!") is used to bring an object to you, wherever it may be. Concentrating is essential to succeeding in the spell; the further away an object is and the larger it is, the harder it is to summon. The two most difficult Summoning Charms are in Goblet of Fire and Order of the Phoenix. In Goblet of Fire, Harry summons his Firebolt from inside the castle to the grounds to use it for the first task of the Triwizard Tournament. In Order of the Phoenix, the potency of the charm is demonstrated when Fred and George Weasley summon their brooms (which were chained to a wall) from another part of the castle.

Alohomora! (Sorcerer's Stone, page 160)
Latin Root: Unknown
The Alohomora Charm (incantation: "Alohomora!") is used to unlock doors or other objects that are locked. The charm also unlocks magically locked doors or objects (see "Colloportus!"). Though the charm comes in handy for Harry, Hermione, and Ron throughout the books, it is not powerful. As shown in Chapter 34, "The Department of Mysteries," in Order of the Phoenix, The Alohomora Charm does not unlock all magically locked doors or objects.

Aparecium! (Chamber of Secrets, page 233)
Latin Root: appareo (to become visible, appear, manifest)
"Aparecium!" is used only once by Hermione in an attempt to reveal the hidden contents of Tom Riddle's diary. Though the spell is unsuccessful, Hermione says that it is used to reveal invisible ink.

Avada Kedavra! (Goblet of Fire, page 215)
Aramaic Root: abracadabra (ancient spell means "let the thing be destroyed")
The Killing Curse (incantation: "Avada Kedavra!") is considered by most wizards the worst curse, as it kills whoever or whatever it is cast upon. The curse is one of three Unforgivable Curses - curses that are illegal and can land a wizard in Azkaban Prison for using them (see "Imperio!" and "Crucio!").

Avis! (Goblet of Fire, page 309)
Latin Root: avis (bird)
"Avis!" is used when examining a wand; it will cause small, twittering birds to fly out of the end of a wand in working condition.

Colloportus! (Order of the Phoenix, page 788)
Latin Root: Unknown
"Colloportus!" is used to lock doors or objects that can be locked. However, the spell is not of much use unless dealing with Muggles or a wandless wizard or witch, because the Alohomora Charm will unlock anything locked by "Colloportus!"

Crucio! (Goblet of Fire, page 214)
Latin Root: crucio (to torture, torment)
The Cruciatus Curse (incantation: "Crucio!") inflicts severe pain on whoever it is cast on. It is used mainly by Voldemort and his Death Eaters when torturing someone. Rowling describes the pain as this: "White-hot knives were piercing every inch of his skin, his head was surely going to burst with pain, he was screaming more loudly than he'd ever screamed in his life..." The length of time the curse is in effect is unknown, but it is presumed to stop after 15 seconds - 1 minute. Wizards and witches (i.e. Frank and Alice Longbottom) can be tortured to the point of insanity by the curse. This explains why the Cruciatus Curse is one of three Unforgivable Curses - curses that are illegal and can land a wizard in Azkaban Prison for using them (see "Avada Kedavra"! and "Imperio!").

Deletrius! (Goblet of Fire, page 136)
Latin Root: deleo (to destroy, wipe out, erase)
"Deletrius!" is used only once throughout the Harry Potter series in order to vanish the "echo" of a spell conjured by Prior Incantato! The incantation comes from the Latin word deleo, which means "to destroy, wipe out, erase." This leads to the assumption that the spell would also delete objects, although this has not been proven by the books.

Densaugeo! (Goblet of Fire, page 309)
Latin Roots: dens (tooth), auctus (growth, enlargement, increase)
"Densaugeo!" causes a person's teeth to grow rapidly. At what point the spell stops is unknown; when Draco hit Hermione with the spell in Goblet of Fire, Hermione's teeth grew down past her collar. The spell can be undone by shrinking the affected teeth.

Diffindo! (Goblet of Fire, page 340)
Latin Root: diffundo (to spread, pour forth, scatter)
"Diffindo!" causes an object to split or break. Wand aim is essential to the success of this spell. It has only been used once in the Harry Potter books (see above reference).

Dissendium! (Prisoner of Azkaban, page 195)
Latin Root: dissimulo - antonym (to conceal, disguise, keep secret)
The incantation "Dissendium!" combined with a tap of the wand will open up the hump of a statue of a humpbacked, one-eyed witch (located on the third-floor corridor of Hogwarts). Going through the opened statue leads to a secret path to the wizard village Hogsmeade.

Engorgio! (Goblet of Fire, page 214)
Latin Root: Unknown
"Engorgio!" causes something to become several times its normal mass. It has only been used once so far in the Harry Potter series (on a spider - see above reference).

Ennervate! (Goblet of Fire, page 133)
Latin Root: Unknown
"Ennervate!" is used to revive persons who have either been knocked unconscious by normal means or by the Stunning Spell, "Stupefy!" When someone is revived by this spell, their eyes suddenly open and they are dazed. They quickly come to their senses and regain composure.

Evanesco! (Order of the Phoenix, page 234)
Latin Root: evanescence (to vanish, to disappear, empty)
"Evanesco!" causes what it is cast upon to disappear. In Order of the Phoenix, the spell is used on scrolls and potions. Whether or not the disappearing object vanishes completely is unknown; a spell to bring the object back may exist, but is not verifiable.

Expecto Patronum! (Prisoner of Azkaban, page 238)
Latin Root: patronus (patron, protector)
The Patronus Charm (incantation: "Expecto Patronum!") is highly advanced magic, well beyond the Ordinary Wizarding Level, used to ward off dementors. When used properly, the spell creates a Patronus, which is a guardian that acts as a shield between the caster and the dementor. Each Patronus is unique to the wizard or witch who conjures it, and reflects their personality. In order for the spell to work properly, the incantation must be spoken while the caster concentrates on a extraordinarily happy memory. This causes a Patronus to be conjured; it is successful in warding off dementors because it is "a projection of the very things that the dementor feeds upon - hope, happiness, the desire to survive - but it cannot feel despair, as real humans can, so the dementors can't hurt it." (Prisoner of Azkaban, page 238)

Expelliarmus! (Chamber of Secrets, page 190)
Latin Root: expello (to drive out, expel, force out, banish)
The Disarming Charm (incantation: "Expelliarmus!") is used to disarm someone, and is most commonly used while dueling. Though a simple spell, it can be used to get wizards and witches out of tight situations and close encounters - it saved Harry Potter's life in Goblet of Fire.

Ferula! (Prisoner of Azkaban, page 376)
Latin Root: Unknown
"Ferula!" creates a splint of bandages, a temporary fix for an injured or broken limb.

Finite Incantatem! (Chamber of Secrets, page 192)
Latin Root: finis (end, limit)
"Finite Incantatem!" is used by Professor Gilderoy Lockhart in Chamber of Secrets, and it stops the effects of both Harry Potter and Draco Malfoy's spells. The spell also works without the "Incantatem" portion of the incantation, which was proved by Remus Lupin in Order of the Phoenix.

Flagrate! (Order of the Phoenix, page 772)
Latin Root: Unknown
"Flagrate!" was used in Order of the Phoenix to mark doors in the Department of Mysteries with a fiery "X". This allowed Harry, Hermione, Ron, Neville, Ginny, and Luna to know which doors they had already gone through.

Furnunculus! (Goblet of Fire, page 298)
Latin Root: Unknown
The Furnunculus Curse (incantation: "Furnunculus!") causes ugly boils to break out all over whoever the curse is cast upon. The Furnunculus Curse should not be mixed with Jelly-Legs; tentacles will sprout all over the victim's face.

Impedimenta! (Goblet of Fire, page 626)
Latin Root: impedimentum (hindrance, impediment, obstacle, difficulty)
"Impedimenta!" slows down an attacker. If the spell is cast upon armor or other metal objects, it will backfire. If the spell is cast upon someone who is standing still, the person standing still will either freeze and be unable to move until they are "unfrozen" or will be knocked off of their feet.

Imperio! (Goblet of Fire, page 214)
Latin Root: imperium (power to command, authority, command, rule, control)
The Imperius Curse (incantation: "Imperio!") is used to control the actions of a person. Although few have the willpower to resist the curse, many wizards and witches cannot. Because wizards can completely control the actions of others when they are under this curse, it is one of the three Unforgivable Curses - curses that are illegal and can land a wizard in Azkaban Prison for using them (see "Avada Kedavra!" and "Crucio!").

Impervius! (Prisoner of Azkaban, page 177)
Latin Root: Unknown
"Impervius!" was used by Hermione Granger on Harry Potter's glasses in the above reference, and it caused them to repel water. The spell was also used on the faces of the players on the Gryffindor Quidditch team in Order of the Phoenix, giving the players better visibility during practice.

Incarcerous! (Order of the Phoenix, page 755)
Latin Root: carcer (prison, cell, jail, dungeon)
"Incarcerous!" has been used only once in the Harry Potter books, by Professor Umbridge (see above reference). When Umbridge cast the spell on Magorian the centaur, "ropes flew out of midair like thick snakes, wrapping themselves tightly around the centaur's torso and trapping his arms."

Incendio! (Goblet of Fire, page 47)
Latin Root: incendia (fire)
"Incendio!" causes a fire to start, and it most commonly used on a fireplace. We are led to the belief that the spell may not work on human beings, due to the fact that it is not an Unforgiveable Curse.

Legilimens! (Order of the Phoenix, page 534)
Latin Root: lego (to gather, choose, collect, pass through, read)
"Legilimens!" is mostly used by accomplished Legilimens, those who can read minds. The spell is used when attempting to break into someone else's mind and access their memories - usually memories that they fear.

Locomotor! (Order of the Phoenix, page 53)
Latin Root: loco (to place, put, position), motor (to move)
"Locomotor!" causes the object(s) that it is cast upon to levitate. Both of the times the spell was used throughout the books, it was cast on a trunk. In order for the spell to work most efficiently, the name of the object should be stated after the word "Locomotor." Example: "Locomotor trunk!" Also, the incantation for the Leg-Locker curse is "Locomotor Mortis!" The Leg-Locker curse causes someone's legs to bind together, making it extremely difficult to move.

Lumos! (Chanber of Secrets, page 302)
Latin Root: luma (light)
"Lumos!" is one of the most commonly used spells, because it is a simple spell and useful. As its Latin root implies, "Lumos!" causes a light to appear at the end of the wand that cast the spell. The incantation "Nox!" is spoken when the bearer of the wand wishes for the light to go out.

Mobili-! (Prisoner of Azkaban, page 201, 377)
Latin Roots: mobili (to move), corpus (body), arbustus (planted with trees)
"Mobili-!" allows the caster to move an object. It has only been used twice throughout the Harry Potter series (see above references), both times with different suffixes. The first usage was by Hermione to move a Christmas tree in the Three Broomsticks. The second was to move the body of Professor Snape, who was unconscious at the time. The spell most likely works on corpses and conscious bodies, but there is no evidence to support this. It is interesting to note that the suffix changes according to the object being moved.

Morsmordre! (Goblet of Fire, page 128)
Latin Root: mors mortis (death)
"Morsmordre!" is the incantation used when a wizard creates the Dark Mark, the sign of Voldemort. The Dark Mark has long been feared, because it was cast over the houses of wizards and witches who had been slain by Voldemort or his Death Eaters.

Nox! (Prisoner of Azkaban, page 338)
Latin Root: nox (darkness)
"Nox!" is used to put out the light created by "Lumos!" The spell presumably does nothing to the caster's wand if "Lumos!" has not previously been cast. The use of the spell on lit objects which are disconnected from the caster's wand is unknown.

Obliviate! (Chamber of Secrets, page 303)
Latin Root: oblivio (forgetfulness, oblivion)
The Memory Charm (incantation: "Obliviate!") causes whoever it is cast upon to lose most of their memory. A variant of this spell may be used for memory modifications, but the spell itself is much more powerful than a mere modification. Though a spell may exist that can bring someone's memory back, it is not commonly known in the wizarding world. In Chamber of Secrets, Professor Lockhart lost most of his memory due to this spell. Though he retained the ability to speak and understand the English language, he could no longer recall many basic things (e.g. names, uses of objects, who he was).

Petrificus Totalus! (Sorcerer's Stone, page 273)
Latin Root: Unknown
The Full-Body Bind (incantation: "Petrificus Totalus!") causes whoever it is cast upon to lose mobility. Rowling describes the effects of the spell best: "Neville's arms snapped to his sides. His legs sprang together. His whole body rigid, he swayed where he stood and then fell flat on his face, stiff as a board....Neville's jaws were jammed together so he couldn't speak. Only his eyes were moving, looking at them in horror."

Point Me! (Goblet of Fire, page 622)
Latin Root: Unknown
The Four-Point spell (incantation: "Point Me!") is used as a directional tool. When the caster places his or her wand in their open palm and utters the incantation, their wand will point north, allowing the caster to know what direction they are going.

Portus! (Order of the Phoenix, page 472)
Latin Root: porta (gate, entrance)
"Portus!" is used to turn an object into a Portkey. Portkeys, first introduced in Goblet of Fire, are seemingly normal objects that transport those in direct physical contact with it to a certain place, usually at a prearranged time. Due to the dangers Portkeys present, authorization is required prior to using the spell. Some Portkeys can be made to transport those in direct physical contact to a certain place the moment they touch it rather than at a prearranged time. Presumably, any object can be turned into a Portkey.

Priori Incantatem! (Goblet of Fire, page 136)
Latin Root: priori prius (former, prior)
The Reverse Spell effect (incantation: "Priori Incantatem!") causes a wand to regurgitate an echo of spells it has performed in reverse. When used in Goblet of Fire on a wand that had conjured the Dark Mark (see "Morsmorde!"), a shadow of the gigantic serpent-tongued skull was emitted from the wand.

Protego! (Order of the Phoenix, page 803)
Latin Root: protego (to protect)
The Shield Charm (incantation: "Protego!") creates a sheild around the caster, protecting them from most harmful spells. Spells exist that can still cause damage to whoever it is cast upon even if The Shield Charm is in use, but the Charm usually saves someone from the worst of the spell cast upon them.

Quietus! (Goblet of Fire, page 116)
Latin Root: quies quietis (quiet, rest, peace)
"Quietus!" is used to counter the effect of the spell "Sonorus!", which amplifies the voice of whoever it is cast upon. "Quietus!" merely makes the voice softer; it does not completely silence it. The spell "Silencio!" completely quiets one's voice.

Reducio! (Goblet of Fire, page 215)
Latin Root: reduco (to lead back, bring back, return)
The Reductor Curse (incantation: "Reducio!") causes solid objects it is cast upon to shrink. If "Engorgio!" has previously been cast on an object, "Reducio!" will cause it to reduce to its original size.

Relashio! (Goblet of Fire, page 496)
Latin Root: Unknown
"Relashio!" presumably shoots sparks at someone; however, the only usage of the spell in the books was underwater. The underwater effect varies - it instead pelts a jet of boiling water at someone.

Reparo! (Goblet of Fire, page 169)
Latin Root: reparo (to restore, renew)
"Reparo!" does exactly what its Latin root suggests - fixes things that are broken. Examples in the Harry Potter books include fixing broken glass, broken china, broken jars, and broken cups. "Reparo!" only works on solid objects.

Rictusempra! (Chamber of Secrets, page 192)
Latin Root: rideo risi risum (to laugh at, laugh)
The Tickling Charm (incantation: "Rictusempra!") causes whoever it is cast upon to start laughing uncontrollably. The effects of the charm can be stopped by the spell "Finite Incanatem!" When the Tickling Charm is cast, a jet of silver light comes out of the caster's wand and hits the victim.

Riddikulus! (Prisoner of Azkaban, page 134)
Latin Root: ridiculus (facetious, laughable)
The spell "Riddikulus!" is used to get rid of a boggart. In order for the spell to work properly, the caster must envision the boggart as something that it finds amusing prior to casting the spell. The spell only turns the boggart into something humorous - what actually gets rid of a boggart is laughter.

Scourgify! (Order of the Phoenix, page 53)
Latin Root: Unknown
"Scourgify!" is used to clean. Examples from the fifth Harry Potter book include cleaning Hedwig the owl's cage and ridding a train compartment of a sticky substance called Stinksap. If cast on someone's mouth, the spell causes pink soap bubbles to stream from their mouth and froth to cover their lips, which chokes the victim.

Serpensortia! (Chamber of Secrets, page 194)
Latin Root: Unknown
"Serpensortia!" causes a long black snake, poised to attack, shoot out of the caster's wand. It has only been used once throughout the Harry Potter series (see above reference).

Silencio! (Order of the Phoenix, page 375)
Latin Root: silens (silent, still)
The Silencing Charm (incantation: "Silencio!") causes whoever it is cast upon to lose the ability to make audible noises. A counter curse most likely exists ("Sonorus!" would probably work), but whoever was affected by the spell, wizard or not, would be unable to utter the incantation for the counter curse. The charm works best with a sharp jab of the wand.

Sonorus! (Goblet of Fire, page 102)
Latin Root: sono (to make a noise, to sing)
"Sonorus!" amplifies your voice in a way similar to that of the muggle "microphone." The spell "Quietus!" will bring the caster's voice back to normal.

Stupefy! (Goblet of Fire, page 129)
Latin Root: stupefactus (stunned)
The Stunning Spell (incantation: "Stupefy!") stuns whoever it is cast upon, knocking them temporarily unconscious. The victim can be brought back to consciousness by the spell "Ennervate!" A normal Stunning Spell will not cause any damage to whoever it is cast upon, but many Stunners cast at once can cause long-term damage.

Tarantallegra! (Chamber of Secrets, page 192)
Latin Root: Unknown
"Tarantallegra!" causes the legs of whoever it is cast upon to jerk around out of control, in a kind of quickstep. The spell is used in the second and fifth Harry Potter books and can be stopped by the spell "Finite Incantatem!"

Waddiwasi! (Prisoner of Azkaban, page 131)
Latin Root: Unknown
The exact effects of the spell are unclear, but the following happened the only time it was used in the Harry Potter books (see above reference): "With the force of a bullet, the wad of chewing gum shot out of the keyhole and straight down Peeves's left nostril." Professor Lupin cast the spell on the piece of chewing gum, which had been stuck in a keyhole by Peeves.

Wingardium Leviosa! (Sorcerer's Stone, page 171)
Latin Root: levo (to raise, lift up)
"Wingardium Leviosa!" causes an object to levitate. Once the caster has an object in the air, it can be moved around with the caster's wand acting as a navigator.