Being a deliverer is not a job for a boy (7)
I believe the answer is:
postman
'being a deliverer is' is the definition.
I can't judge whether this definition defines the answer.
'a job for a boy' is the wordplay.
'a job' becomes 'post' (post is a kind of job).
'for' is a charade indicator (letters next to each other).
'a boy' becomes 'man' ().
'post'+'man'='POSTMAN'
'not' is the link.
Can you help me to learn more?
(Other definitions for postman that I've seen before include "Mail deliverer" , "Chap with letters" , "TV's Pat, for instance" , "Male mail carrier" , "No stamp needed, stangely, for this job" .)