Fellow, comrade (9)
I believe the answer is:
companion
<span class="explanation-format__ClueExplanation">I believe this clue is a double definition.<br/ ><br/ >'<span class="explanation-format__original">fellow</span>' is the first definition.<br/ ><span class="explanation-format__explanation">(I know that fellow can be written as companion)</span><br/ ><br/ >'<span class="explanation-format__original">comrade</span>' is the second definition.<br/ ><span class="explanation-format__explanation">(I know that comrade can be written as companion)</span><br/ ><br/ ></span>
(Other definitions for companion that I've seen before include "One of a pair" , "Ladder" , "Mate (maybe of honour!)" , "Fellow traveller" , "Person who lives or travels with you" .)