Very steep rock face (9)
I believe the answer is:
precipice
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">very steep rock face</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for precipice that I've seen before include "High vertical cliff" , "Sheer cliff" , "Sheer drop" , "(Overhang of) steep cliff" , "Steep cliff face" .)