Meeting doesn’t start for companion (4)
I believe the answer is:
ally
'companion' is the definition.
(thesaurus)
'meeting doesn't start' is the wordplay.
'meeting' becomes 'rally' (I have seen 'Mass meeting ' mean 'rally' so perhaps 'meeting' could also mean 'rally').
'doesn't start' means to remove the first letter.
'rally' with its first letter taken off is 'ALLY'.
'for' is the link.
(Other definitions for ally that I've seen before include "Supporter in a conflict" , "mate" , "Accomplice" , "Friend and colleague" , "Join forces with" .)