Darling perhaps of chauffeur who'd lost his head (5)
I believe the answer is:
river
'darling perhaps' is the definition.
(I know that Darling River is a river)
I don't understand the remainder of the clue.
Can you help me to learn more?
(Other definitions for river that I've seen before include "Eg, Thames or Nile" , "Large natural stream of water" , "Eg, Amazon" , "Tees, perhaps" , "Natural flow of water" .)