A negative back-formation from apparition (see usage notes).
- To disappear (magically)
- ... the simplest thing [he] could do, to help secure a fourth term for Labour, would be to disapparate, taking his fellow revenants with him. ( - The Observer)
The word was invented by J. K. Rowling in the Harry Potter books to describe a form of teleportation from one place to another, but in derived usage it often means just to disappear completely.