In room-and-pillar mining, to extract a deposit of rock by breaking down a pillar which had been holding it in place.
To engage in the recreational exploration of caves.
To hollow out or undermine.
To surrender.
To collapse.
A code cave.
A hole, depression, or gap in earth or rock, whether natural or man-made.
A large, naturally-occurring cavity formed underground or in the face of a cliff or a hillside.
A shielded area where nuclear experiments can be carried out.
A storage cellar, especially for wine or cheese.
A place of retreat, such as a man cave.
A naturally-occurring cavity in bedrock which is large enough to be entered by an adult.
Debris, particularly broken rock, which falls into a drill hole and interferes with drilling.
A group that breaks from a larger political party or faction on a particular issue.
A collapse or cave-in.
The vagina.
look out!; beware!
To vault over something using a pole vault
To perform a pole vault