Hardly a job for a mere boy (7)
I believe the answer is:
postman
'hardly a job for a mere boy' is the definition.
I can't tell whether this definition defines the answer.
'job for a mere boy' is the wordplay.
'job' becomes 'post' (post is a kind of job).
'for' means one lot of letters go next to another.
'a mere boy' becomes 'man' (I am not sure about the 'mere' bit.).
'post'+'man'='POSTMAN'
Can you help me to learn more?
(Other definitions for postman that I've seen before include "Mail deliverer" , "TV's Pat, for instance" , "Chap with letters" , "Letter deliverer" , "Male mail carrier" .)