Rugged cliff (4)
I believe the answer is:
crag
'rugged cliff' 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 "Steep or rugged cliff face" , "Avant-garde" , "Rocky hilltop" , "Steep rugged rock or cliff" , "Steep rocky cliff" .)