101 Magical Spells: Words of Wizardry from the World of Harry Potter (Part 4: M-Q)

Mobili-!
Word Origin: From the Latin mobili (to move) and arbor (tree)
Purpose: This incantation allows the caster to move an object. It is used with a suffix, which varies with the target object.
Example: In Harry Potter and the Prisoner of Azkaban, Remus Lupin uses the incanttion "Mobilicorpus" to move the unconscious body of Professor Snape from the Shrieking Shack. The suffix -corpus is Latin for "body". Hermione uses "Mobiliarbus" to move a Christmas tree. The suffix -arbus is from the Latin arbor (Tree)

Morsmordre!
Word Origin: From the Latin mors (death) and mordere (to bite).
Purpose: This incantation is used to conjure the much-feared Dark Mark - the sign of Voldemort. The Mark is a huge, glowing skull in the sky, which has a snake coming out of its mouth. It is used by the Death Eaters, who cast it into the sky when they have murdered a wizard or witch.
Example: In Harry Potter and the Goblet of Fire, it is conjured at the 1994 Quidditch World Cup.

Muffliato!
Word Origin: From the English muffle (to deaden sound)
Purpose: The spell is used to keep people close by from eavesdropping on a conversation, by filling their ears with a light, undetectable buzzing.
Example: In Harry Potter and the Half-Blood Prince, this is another of the spells that Harry learns from Slope's notes. However, Hermione disapproved of using it, threatening to not talk at all if Harry cast it on anyone around them.

Nox!
Word Origin: From the Latin nox (night)
Purpose: This is the counter-incantation for "Lumos," which lights up the tip of the caster's wand. Nox! puts out this light.
Example: In Harry Potter and the Prisoner of Azkaban, Harry and Hermione cast this spell in the Shrieking Shack, to put out their lighted wands.

Obliviate!
Word Origin: From the Latin oblivio (forgetfulness, oblivion)
Purpose: This is the incantation for the Memory Charm, used to erase portions of the victims memory.
Example: In Harry Potter and the Prisoner of Azkaban, this spell is cast upon witnesses to Peter Pettigrew's murder of twelve Muggles and his escape as a rat