0 a hole in the ground, especially in an area of limestone rock, that has been formed naturally, for example by water that has worn away the rock:
1 part of a computer network or server to which internet activity is directed so that it cannot damage the part it is being aimed at:
2 to direct internet activity to a different part of a network or server, so that it cannot damage the part it is being aimed at:
The valley has been intensely karstified, as evidenced by the numerous sinkholes, springs, caves, and disappearing streams.
Water erosion has left the calcareous plateaus strewn with dolines and poljes (sinkholes and flat-floored depressions).
The animals apparently fell to their deaths tens of metres below, through narrow openings in the roof of the caves known as sinkholes.
As a solution to the cholera problem, city officials constructed a sewer system to drain sinkholes that had become clogged with sewage and garbage.
Sinkholes appear in hallways because outdoor sewage and drainage systems are outdated.
Several sinkholes, some huge, have opened within the city.
Karst is characterized by dissolved limestone formations such as sinkholes and haystack-shaped hills known as mogotes.
All ramps and sinkholes are worth 5,000,000 for 30 seconds.