Protego.
collportus
The incantation Protego activates a Shield Charm.
The incantation for the Patronus Charm is "Expecto Patronum!"
Protego!Protego is the shield charm, a spell that creates an energy barrier which deflects minor to moderate hexes as well as physical objects. It will not repell any Unforgivable Curse. The Shield Charm is a moderately difficult spell. Fred and George Weasley realized that most adult wizards, even those employed by the Ministry of Magic, could not produce a functional Shield Charm. They used this to their advantage when marketing their line of protective clothing (hats, cloaks, etc), upon which Shield Charms were cast.
It was the Protean Charm, what the incantation was to cast this charm was never revealed however.
carmen, carminis, n. - song, chant, incantation, charm
The shield charm protect somone from a spell for a little while
The word incantation means a series of words said as a magic spell or charm. Therefore, incantations aren't generally seen nowadays in places apart from fantasy games, books and movies.
Oblivate is the incantation for a memory charm in Harry Potter. Gilderoy Lockhart didn't invent them or anything, he just happened to be quite good at them.
the "Rasputinarius" Charm. The incantation is "Rasputinario!" and it involves some special wand work. It's in The Standard Book of Spells, Grade 5.
Blue Incantation was created in 1995.
Her prose too often resorts to incantation. The incantation echoed for several minutes after she finished the words.
The Ultimate Incantation was created in 1992-11.