The Eradication Spell (Deletrius) is used to disintegrate or remove certain things.
Discovered in Book 4, Chapter 9[]
Deletrius is used by Amos Diggory to remove the shadow of the Dark Mark conjured from Harry's wand by the spell Priori Incantatum.
Reference[]
1.http://www.pottermore.com/en/book4/chapter9/moment1/eradication-spell