### Clue: Normand — one in supporting role as a rule (8)
### Answer: NORMALLY 
 ### Explanation: reference to Mabel Normand 
*Thanks to AlanC + George+K*: "Normand" becomes 'Norm / and', so NORM and ALLY="one in supporting role"
 
~~NORM (short for Normand) + ALLY="one in supporting role"~~