One who delivers coming after us? (7)
I believe the answer is:
postman
'one who delivers coming' is the definition.
The answer is a person as well as being a singular noun. This is suggested by the definition.
'after us?' is the wordplay.
'after' becomes 'post' (prefix meaning after, eg post-war).
'us?' becomes 'man' (I've seen this before).
'post'+'man'='POSTMAN'
Can you help me to learn more?
(Other definitions for postman that I've seen before include "TV's Pat, for instance" , "Male mail carrier" , "Letter deliverer" , "Mail deliverer" , "one delivers" .)