Evaluate, rate (6)
I believe the answer is:
assess
I believe this clue is a double definition.
'evaluate' is the first definition.
(synonyms)
'rate' is the second definition.
(to assess is to rate or evaluate)
(Other definitions for assess that I've seen before include "Evaluate (quality)" , "Gauge, evaluate" , "Estimate, gauge" , "Rate, evaluate" , "Evaluate, estimate" .)