### Clue: Fine musical returns, featuring unknown old minx (6)
### Answer: FIZGIG 
 ### Explanation: Definition: old minx
  F(abbrev. for "fine") + **reversal of**(… returns) GIGI(the stage and film musical based on a Collette novella) **containing**(featuring) Z(symbol for an unknown quantity in mathematics).
Defn: An old term for a flirtatious young woman.