Older, higher in rank (6)
I believe the answer is:
senior
This clue is a double definition.
'older' is the first definition.
(similar in meaning)
'higher in rank' is the second definition.
(I've seen this before)
(Other definitions for senior that I've seen before include "High-ranking" , "Higher in rank or age" , "Elder person - higher in rank" , "More advanced in years or authority" , "Being old" .)