Protego Totalum was the incantation for the defensive spell used to protect a small area from most other spells for extended periods. It formed a protective "bubble" around the area it was cast in. This spell was used by Hermione Granger along with other charms to prevent attacks from Death Eaters as she, Ron and Harry traveled in search of Voldemort's Horcruxes following his rise to power.
Appearances
Harry Potter and the Deathly Hallows