A rockfall or rock-fall  refers to quantities of rock falling freely from a cliff face. The term is also used for collapse of rock from roof or walls of mine or quarry workings. A rockfall is a fragment of rock (a block) detached by sliding, toppling, or falling, that falls along a vertical or sub-vertical cliff, proceeds down slope by bouncing and flying along ballistic trajectories or by rolling on talus or debris slopes,” (Varnes, 1978). Alternatively, a "rockfall is the natural downward motion of a detached block or series of blocks with a small volume involving free falling, bouncing, rolling, and sliding". The mode of failure differs from that of a rockslide.
- Whittow, John (1984). Dictionary of Physical Geography. London: Penguin, 1984. Template:ISBN.