Senior angel possibly taking a rise out of a saint! (6)
I believe the answer is:
sister
'senior angel' is the definition.
The answer and definition can be both people as well as being singular nouns.
Perhaps they are linked in a way I don't understand?
'taking a rise out of a saint' is the wordplay.
'taking' becomes 'reis' (I can't explain this - if you can you should give a lot more credence to this answer).
'a rise' is a reversal indicator.
'out of' is an insertion indicator (some letters on the outside of others).
'a saint' becomes 'st' (abbreviation).
'reis' back-to-front is 'sier'.
'sier' placed around 'st' is 'SISTER'.
'possibly' acts as a link.
Can you help me to learn more?
(Other definitions for sister that I've seen before include "The nurse in charge" , "Senior nurse; relative" , "of the same origin" , "twin?" , "Martin --, film director" .)