Type: Charm
Pronunciation: AH-par-EE-see-um
Description: Reveals secret messages written in invisible ink, or any other hidden markings. Also works against Concealing charms
Seen/Mentioned: Used (to no avail) in 1993 by Hermione Granger to attempt to reveal any hidden writing in a diary.
Etymology: Latin apparere, meaning "to appear"; -ium and -cium are common Latin noun endings.