Appalled that contents of bag has tobacco (6)
I believe the answer is:
aghast
'appalled' is the definition.
(synonyms)
'contents of bag has tobacco' is the wordplay.
'contents of' indicates a hidden word.
'AGHAST' can be found hidden inside 'bag has tobacco'.
'that' is the link.
(Other definitions for aghast that I've seen before include "Amazed" , "Horror-struck" , "Filled with horror or shock" , "Appalled, filled with consternation" , "What's carried in bag has teacher" .)