His is not one of those jobs for the boys (7)
I believe the answer is:
postman
'his' is the definition.
The answer is a person as well as being a singular noun. This is suggested by the definition.
'not one of those jobs for the boys' is the wordplay.
I cannot really understand how this works, but
'not' could be 'o' (I've seen this in other clues) and 'o' is found in the answer.
'one' could be 'an' (an apple is one apple) and 'an' is found in the answer.
'the' could be 't' (the is pronounced as a 't' sound in some dialects) and 't' is located in the answer.
This may be the basis of the clue (or it may be nonsense).
'is' acts as a link.
Can you help me to learn more?
(Other definitions for postman that I've seen before include "No stamp needed, stangely, for this job" , "Male mail carrier" , "Letter deliverer" , "Mail deliverer" , "TV's Pat, for instance" .)