Returning obstetrician thanks guy who ferried him across (7)
I believe the answer is:
boatman
'ferried him across' is the definition.
The answer is a person as well as being a singular noun. This is suggested by the definition.
'returning obstetrician thanks guy' is the wordplay.
'returning' shows that the letters should be reversed in order.
'obstetrician' becomes 'OB'.
'thanks guy' becomes 'atman' (I can't explain this - if you can you should believe this answer much more).
'ob' backwards is 'bo'.
'bo'+'atman'='BOATMAN'
'who' is the link.
Can you help me to learn more?
(Other definitions for boatman that I've seen before include "Fellow with craft" , "Sailor" , "One having row with" , "He may have a smack" , "George - or Harris, maybe" .)