Role for Catholic woman once in charade — a con, essentially (9)
I believe the answer is:
deaconess
'role for catholic woman' is the definition.
(female deacon)
'in charade a con essentially' is the wordplay.
'in' indicates a hidden word.
'DEACONESS' can be found hidden inside 'charade a con essentially'.
'once' acts as a link.
(Other definitions for deaconess that I've seen before include "Minister" , "Female lay official of the church" .)