Geminio (Doubling Charm)
Gemino Curse
Type: Charm
Pronunciation: jeh-MIH-nee-oh
Description: Duplicates the target. When used to duplicate objects indefinitely on purpose, is known as the Gemino Curse.
Seen/Mentioned: Used by Hermione Granger on Salazar Slytherin's Locket to disguise her presence from Dolores Umbridge.
Etymology: The Latin word gemini means "twins".
Glacius (Freezing Spell)
Glacius
Type: Charm
Pronunciation: GLAY-see-us
Description: Freezes the target with icy-cold air.
Etymology: From Latin glacies, which means "ice".
Notes: Not to be confused with the Freezing Charm, which merely immobilises things.
Glacius Duo
Type: Charm
Pronunciation: GLAY-see-us DOO-oh
Description: A more powerful version of Glacius.
Etymology: From Latin glacies, which means "ice".
Glacius Tria
Type: Charm
Pronunciation: GLAY-see-us TREE-ah
Description: A more powerful version of Glacius Duo.
Etymology: From Latin glacies, which means "ice".
Glisseo
Type: Charm
Pronunciation: GLISS-ee-oh
Description: Causes the steps on a stairway to flatten into a slide.
Seen/Mentioned: Used by Hermione Granger to escape from Death Eaters.
Etymology: Probably derived from French glisser, meaning "to slide".
(Green Sparks)
Description: Jet of green sparks that can be used to signal an emergency or as a minor duelling spell.
Seen/Mentioned: Taught in Defence Against the Dark Arts; When Hagrid, Harry and Hermione try to find an injured unicorn, Hagrid says that if it is found, they must send up green sparks.
Notes: The incantation is almost certainly Verdimillious.
(Gripping Charm)
Type: Charm
Description: Helps someone grip something more effectively.
Seen/Mentioned: Used on Quaffles to help Chasers carry them.
(Gytrash-conjuring spell)
GytrashConjuring
Type: Conjuration, Dark Arts
Description: Conjures luminous green Gytrashes from the wand, which can be commanded by the caster to attack an opponent.