No rise for those more advanced in service (6)
I believe the answer is:
senior
'in service' is the definition.
Both the definition and answer are adjectives. Perhaps you can see an association between them that I can't see?
'no rise for those more advanced' is the wordplay.
'no rise' can be anagrammed to 'SENIOR'.
Though, I am not clear how this is indicated.
Can you help me to learn more?
(Other definitions for senior that I've seen before include "Older or higher in standing" , "'Older, superior (6)'" , "High in rank" , "Pupil in a higher form" , "Higher in rank or age" .)