Appalling, awful (8)
I believe the answer is:
dreadful
I believe this clue is a double definition.
'appalling' is the first definition.
(I've seen this before)
'awful' is the second definition.
(I know that awful can be written as dreadful)
(Other definitions for dreadful that I've seen before include "Dire, alarming" , "Appalling, awful" , "Extremely bad or disagreeable" , "Atrocious, awful" , "Horrible, shocking" .)