Old witch from Carthage (3)
I believe the answer is:
'old witch' is the definition.
(I've seen this in another clue)
'from carthage' is the wordplay.
'from' says the answer is hidden in the clue.
'HAG' is hidden within 'carthage'.
(Other definitions for hag that I've seen before include "Witch or ugly old woman" , "Crone" , "Old witch-like woman" .)