### Clue: Green train is not heading for Milton Keynes? (9)
### Answer: ECONOMIST 
 ### Explanation: Definition: Keynes?

**ECO** ("green") +** *(is not m)** [anag:*train*] where M is [*heading for*] M(ilton)
 
*Refers to John Maynard Keynes (1883-1946)