He's known to be hungry for pursuit (6)
I believe the answer is:
hunter
'he's known to' is the definition.
The answer is a person as well as being a singular noun. This is suggested by the definition.
'hungry for pursuit' is the wordplay.
'hungry' becomes 'er' (I am not sure about this - if you are sure you should give a lot more credence to this answer).
'for' is a charade indicator (letters next to each other) (I've seen this in other clues).
'pursuit' becomes 'hunt' (synonyms).
'er' after 'hunt' is 'HUNTER'.
'be' is the link.
Can you help me to learn more?
(Other definitions for hunter that I've seen before include "One pursuing - type of watch" , "woodsman" , "See 10" , "Orion -- pocket watch with a hinged protective lid" , "One seeking game" .)