Companion suffering nip (5)
I believe the answer is:
chill
'nip' is the definition.
(I've seen this before)
'companion suffering' is the wordplay.
'companion' becomes 'ch' (I've seen this in other clues).
'suffering' becomes 'ill'.
'ch'+'ill'='CHILL'
(Other definitions for chill that I've seen before include "Make cooler" , "Make cool" , "nip" , "Cool, coolness" , "Slight cold" .)