Is Capone able to identify a watercourse? (5)
I believe the answer is:
canal
'a watercourse?' is the definition.
(I've seen this before)
'is capone able' is the wordplay.
I cannot really see how this works, but
'capone' could be 'al' and 'al' is found in the answer.
'able' could be 'can' and 'can' is found within the answer.
This accounts for all the letters.
This explanation may well be incorrect...
'to identify' acts as a link.
(Other definitions for canal that I've seen before include "Artificial waterway for barges" , "Man-made channel of water" , "Passage" , "Duct" , "Man-made strip of water" .)