Debris, particularly broken rock, which falls into a drill hole and interferes with drilling.
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.
A group that breaks from a larger political party or faction on a particular issue.
A collapse or cave-in.
The vagina.
To engage in the recreational exploration of caves.
To hollow out or undermine.
To surrender.
In room-and-pillar mining, to extract a deposit of rock by breaking down a pillar which had been holding it in place.
To collapse.
look out!; beware!
A tool used to bore through rock when sinking shafts.
A surgical instrument used to remove a circular section of bone from the skull; a trephine.
To create a large hole by making a narrow groove outlining the shape of the hole and then removing the plug of material remaining by less expensive means.
To use a trepan; to trephine.