Amicable relationship
I believe the answer is:
rapport
'amicable relationship' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for rapport that I've seen before include "Sympathetic relationship" , "Mutual sympathy" , "Harmonious and understanding relationship between people" , "Feeling of affinity and harmony" , "Harmonious understanding with someone" .)