Most senior (6)
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">most senior</span>' is the definition.<br/ ><span class="explanation-format__explanation">('old' can be similar in meaning to 'senior')</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for oldest that I've seen before include "First in time" , "Least young" , "Most aged" , "Least recent" , "Most ancient (O, not E)" .)
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">most senior</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for eldest that I've seen before include "Most advanced in years" , "Such as Cain, say" , "Firstborn; led set (anag.)" , "Most senior in age" , "First in the order of birth" .)