Environment settling on fortunate compromise (5,6)
I believe the answer is:
happy medium
'compromise' is the definition.
(I've seen this before)
'environment settling on fortunate' is the wordplay.
I cannot really understand how this works, but
'environment' could be 'medium' (medium is a kind of environment) and 'medium' is present in the answer.
'fortunate' could be 'happy' (similar in meaning) and 'happy' is found in the answer.
This accounts for all the letters.
This explanation may well be incorrect...
Can you help me to learn more?
(Other definitions for happy medium that I've seen before include "avoidance of extremes" , "Sensible middle way" , "pleased spiritualist" , "satisfied spirited interpreter" , "result of successful session with board?" .)