stalactite
/stəˈlækˌtaɪt/
noun
- A long, thin piece of rock that hangs down from the ceiling of a cave, formed by dripping water containing minerals.
- The cave was filled with beautiful stalactites that looked like icicles made of stone.
- Tourists wore hard hats to protect their heads from the sharp stalactites above.
- A single drop of water can take hundreds of years to form a stalactite.