His pursuit is baseball (7)
I believe the answer is:
catcher
This clue could be a double definition.
'his pursuit' is the first definition.
The answer is a person as well as being a singular noun. This is suggested by the definition.
'baseball' is the second definition.
The definition and answer can be both acts as well as being singular nouns.
Maybe you can see a link between them that I can't see?
'is' is the link.
Can you help me to learn more?
(Other definitions for catcher that I've seen before include "booked in the rye" , "Famous Salinger novel ''The . . . . . . . In the Rye''" , "Baseball fielder" , "fisherman maybe" , "Baseball player - in the rye?" .)