Dissendium

Dissendium is the incantation for the charm which reveals hidden passages.

dis·sen·di·um
/dis’en’dē’əm/
noun

Dissendium History

The passageway behind the one-eyed witch statue located inside Hogwarts Castle in the third floor corridor can be opened using this incantation. May be a single purpose spell, though it may work on other similar passages as well.