Spelunker
One who explores caves as a sportsman or amateur speleologist.
Stalactite
A calcite speleothem which grows downward, icicle-fashion, as a result of deposition by dripping water.
Stalagmite
A calcite speleothem which grows upward from a cave floor as a result of deposition by dripping water.
Vadose zone
The region lying between the surface of the earth and the water table. Water which seeps or flows through this region under the pull of gravity is called vadose water.
Water table
The meeting place of the phreatic and vadose zones. Below it, the rock is saturated with water; above it, water under the pull of gravity is continuously flowing downward.