Pale with shock (5)
I believe the answer is:
ashen
'pale with shock' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for ashen that I've seen before include "Pale (with shock/illness)" , "White" , "'Very pale, from shock say (5)'" , "Pale of face, quite grey" , "(Of face) pale (with shock)" .)