Rugged rock face (4)
I believe the answer is:
crag
'rugged rock face' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for crag that I've seen before include "Rough, steep rock face" , "Steep rugged rock or cliff" , "Steep, overhanging rock" , "Steep or rugged cliff face" , "Steep rock, peak" .)