Companion; mate (6)
I believe the answer is:
friend
I believe this is a double definition.
'companion' is the first definition.
(I've seen this before)
'mate' is the second definition.
(I've seen this before)
(Other definitions for friend that I've seen before include "One who gives proof of genuine regard" , "Organisation's supporter" , "Associate, supporter" , "Pal, amigo" , "Pal, mate" .)