Saint growing old but performing dramatically (7)
I believe the answer is:
staging
'performing dramatically' is the definition.
'staging' can be an answer for 'performing' (performing on stage). I am not sure about the 'dramatically' bit.
'saint growing old' is the wordplay.
'saint' becomes 'st' (abbreviation).
'growing old' becomes 'aging' (I've seen this before).
'st'+'aging'='STAGING'
'but' is the link.
Can you help me to learn more?
(Other definitions for staging that I've seen before include "Putting on a show" , "Mounting (a play)" , "Putting on (a play)" , "in the greenhouse" .)