A spell which opened a secret passage inside a statue.

Dissendium is the incantation of a charm that reveals hidden passageways, particularly the one behind the statue of the one-eyed witch in the third corridor at Hogwarts castle.

While initially this appears to be a simple password for the statue, it was used in other media in an attempt to open lockets, out of frustration.

It is unknown what may happen if Dissendium is used on something else besides passageways, for example it caused a small explosion when it was used in a failed attempt to destroy the locket.