Lives a double life at Oxford (4)
I believe the answer is:
isis
'life at oxford' is the definition.
I can't judge whether this definition defines the answer.
'lives a double' is the wordplay.
'lives' becomes 'is' ('be' can be a synonym of 'live').
'a double' shows that letters should be duplicated.
'is' doubled is 'ISIS'.
Can you help me to learn more?
(Other definitions for isis that I've seen before include "Oxfordshire river" , "River Thames at Oxford" , "Egyptian goddess - Thames at Oxford" , "Revered figure" , "The goddess lives twice" .)