Point wand at victim
Affixes tongue to the roof of the mouth
- "Harry aimed his wand at Peeves and said, "Langlock!" Peeves clutched at his throat, gulped, then swooped from the room making obscene gestures but unable to speak, owing to the fact that his tongue had just glued itself to the roof of his mouth."
- —Harry Potter's use on Peeves the Poltergeist in the Hogwarts hospital wing[src]
- Harry Potter used Langlock on Argus Filch twice during the 1996-1997 school year, and again on Peeves.
The word langue is the root for tongue
- Harry Potter and the Half-Blood Prince (First appearance)