An understanding supporter (8)
I believe the answer is:
follower
This might be a double definition.
'an understanding' is the first definition.
Although both the answer and definition are singular nouns, I cannot see how one could define the other.
'supporter' is the second definition.
(I've seen this before)
Can you help me to learn more?
(Other definitions for follower that I've seen before include "Attendant" , "One accepts the leadership of another" , "Supporter" , "fan" , "A loyal adherent - or a pursuer" .)