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)
Latin Root: Unknown
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: Unknown
" 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." This leads us to the conclusion that Umbridge may not be a powerful witch as both Snape(PoA) and Quirrel(PS) could conjourropes without saying the incantation (Snape pointed his wand at lupin and the ropes shot out while Quirrel simply clapped his hands and ropes came out of nowhere to bind Harry)

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.

Mobilicorpus! (Prisoner of Azkaban, page 377)
Latin Roots: mobili (to move), corpus (body)
" Mobilicorpus!" allows the caster to move someone else's body. It has only been used once throughout the Harry Potter series (see above reference), 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.

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.