Brownish uniform? (6)
I believe the answer is:
livery
This could be a double definition.
'brownish' is the first definition.
Both the answer and definition are adjectives. Perhaps there's an association between them I don't understand?
'uniform?' is the second definition.
(livery is a type of formal uniform)
Can you help me to learn more?
(Other definitions for livery that I've seen before include "Horse maintenance" , "Uniform -- suffering from gastric distress" , "colours" , "Feeding and stabling of horses for money" , "The care of horses for pay" .)