Heading for Piccadilly Nimrod leaves Henry with client (6)
I believe the answer is:
punter
'client' is the definition.
The answer and definition can be both people as well as being singular nouns.
Maybe they are linked in a way I don't understand?
I can't explain the rest of the clue.
Can you help me to learn more?
(Other definitions for punter that I've seen before include "boater" , "Person who bets" , "One betting; 4's prey (slang)" , "Informally, a customer or someone who bets" , "A colloquial better or a regular client" .)