"From budding Herbologists digging for Snargaluff seedlings to treasure-hunting curse breakers uncovering ancient wizard tombs the Gouging Spell makes all manner of heavy labour a matter of pointing a wand."
-- Miranda Goshawk (BoS)
Digs through or hollows out the target, can be used on earth and stone.
References from the canon
Cast by Hermione (who was then joined by Harry and Ron) to help the dragon enlarge the passageway (DH26).
The spell is used by Herbologists for digging, as well as curse breakers digging for tombs (BoS).
"defodio" L. dig down, hollow out