Appalled hag sat shivering (6)
I believe the answer is:
aghast
'appalled' is the definition.
(synonyms)
'hag sat shivering' is the wordplay.
'shivering' is an anagram indicator.
'hag'+'sat'='hagsat'
'hagsat' with letters rearranged gives 'AGHAST'.
(Other definitions for aghast that I've seen before include "Horror-stricken, filled with consternation" , "Filled with fear and consternation" , "Appalled, filled with consternation" , "Filled with fear or horror" , "Deeply dismayed" .)