Ranking (6)
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">ranking</span>' is the definition.<br/ ><span class="explanation-format__explanation">(similar in meaning)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for senior that I've seen before include "Elder person - higher in rank" , "Elder (of two)" , "High-ranking" , "'Older, superior (6)'" , "More advanced in years or authority" .)
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">ranking</span>' is the definition.<br/ ><span class="explanation-format__explanation">('grade' can be a synonym of 'rank')</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Another definition for grading that I've seen is " Ranking in order".)