### Clue: Barclays thought him such a geezer – for a time (7)
### Answer: DIAMOND 
 ### Explanation: Definition: Barclays thought him such a geezer – for a time
 Cryptic defn: Robert Diamond was the CEO of Barclays, which company thought he was such a "diamond geezer ",a precious chap for a time, until he, and Barclays, got into trouble.