Homenum Revelio is a charm which reveals human presences in the surrounding environment. The spell indicates a body by a marker, the appearance of which is yet unknown, but which can be felt by the target as something "swooping" low over him or her.
In 1997, Hermione Granger used this spell at 12 Grimmauld Place after escaping pursuing Death Eaters. Later that year, Death Eaters used this spell to locate Harry Potter at Xenophilius Lovegood's house. It may have been used in 1991 by Dumbledore to detect Harry under his Invisibility cloak.
Etymology
The Latin word Homo/Hominis means "person" and Latin revelo means "to unveil".
Behind the scenes
- J.K. Rowling stated that Albus Dumbledore could cast a non-verbal Homenum Revelio charm. This is the reason he was able to know Harry was present even while under the Invisibility cloak[1].