In a state of equilibrium (8)
I believe the answer is:
balanced
'in a state of equilibrium' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for balanced that I've seen before include "Composed - unbiased" , "In a state of equilibrium" , "Stable - poised" , "Equitable" , "With both sides equal" .)