Densaugeo

Densaugeo is the incantation of a hex, the victim’s teeth enlarge rapidly.

Den·sau·geo
/den’sô’jēō/
noun

Densaugeo History
At Hogwarts School of Witchcraft and Wizardry, this hex is sometimes taught in Defence Against the Dark Arts in their fifth year. This hex was once used in a duel at Hogwarts between Draco Malfoy and Harry Potter, the intended victim, Potter, was not hit, but Hermione Granger, the current Minister for Magic (as of 2019), was hit when the spell astray.

Densaugeo Etymology 
The incantation “desgaugeo” is Latin, and is derived from the words “dens” and “augeo” which mean “tooth” and “increase” respectively.