Rumbling bad sign for tummy (7)
I believe the answer is:
abdomen
'for tummy' is the definition.
(I've seen this before)
'rumbling bad sign' is the wordplay.
I cannot really see how this works, but
an anagram of 'bad' is 'abd' which is located in the answer.
'sign' could be 'omen' (omen is a kind of sign) and 'omen' is found within the answer.
No letters remain.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for abdomen that I've seen before include "Part of body containing the digestive organs" , "Ban demo (anag)" , "gut" , "Belly" , "Central part of the body" .)