Reveals human presence in the target area.
References from the canon
Cast by Hermione just after she, Ron, and Harry entered number twelve, Grimmauld Place (DH9).
Magic Type Magical effect
Incantation Homenum revelio
Pronunciation HOM-eh-num reh-VEL-ee-oh
"homoinis" L. human being + "revelo" L. to unveil, uncover