Kin's partner (4)
I believe the answer is:
kith
'kin's partner' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for kith that I've seen before include "'... and kin, friends and relations (4)'" , "knowledge" , "Friends and acquaintances" , "Friends (archaic)" , "Friends and neighbours, not family" .)