Fellow, comrade (9)
I believe the answer is:
companion
I believe this clue is a double definition.
'fellow' is the first definition.
(I know that fellow can be written as companion)
'comrade' is the second definition.
(I know that comrade can be written as companion)
(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" .)