He needs no stamp (7)
I believe the answer is:
postman
'he' is the definition.
The answer is a person as well as being a singular noun. This is suggested by the definition.
'no stamp' is the wordplay.
'no stamp' anagrams to 'POSTMAN'.
However, I am unsure how the anagram is indicated.
'needs' is the link.
Can you help me to learn more?
(Other definitions for postman that I've seen before include "Mail deliverer" , "Male mail carrier" , "one delivers" , "Male to deliver mail" , "Chap with letters" .)