Point wand at ground
Forces a target to the ground.
Deprimo is a charm which places immense downward pressure upon a target, which may cause the target to fracture.
Hermione Granger used this spell in 1998 to facilitate the escape of Harry Potter, and Ron Weasley, and herself from the Lovegood House. She blasted through a floor so that she, Harry, and Ron fell through, and then Disapparated them in the air.
The incantation for this spell is most likely derived from the Latin deprimo, meaning "I press down" or "dig deep"