Rough projection (4)
I believe the answer is:
'rough projection' 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" , "Steep, overhanging rock" , "Steep rock, peak" , "Steep, rugged peak" , "Steep rocky cliff" .)