rockfall
/ˈrɒkfaʊl/Definitions
1. noun
a sudden release of rock or stones from a cliff or mountainside, typically caused by weather or erosion
“The hikers had to navigate through a section of steep terrain that was prone to rockfalls.”
2. verb
to break off or come away suddenly from a rock face or cliff
“The earthquake caused the rocks to rockfall down the mountain.”