The ancient goddess lives again (4)
I believe the answer is:
isis
'the ancient goddess' is the definition.
'Isis' can be an answer for 'goddess' (Egyptian god). I am not certain of the 'the ancient' bit.
'lives again' is the wordplay.
'lives' becomes 'is' ('be' can be a synonym of 'live').
'again' becomes 'is' (I can't explain this - if you can you should give a lot more credence to this answer).
'is'+'is'='ISIS'
Can you help me to learn more?
(Other definitions for isis that I've seen before include "Si, si - an Egyptian goddess" , "Egyptian fertility goddess, mother of Horus" , "Egyptian goddess and jihadist group" , "Oxford's second crew" , "River Thames at Oxford" .)