Brigadier's wild rage on the road (6)
I believe the answer is:
gerard
'brigadier's' is the definition.
Both the answer and definition are singular nouns.
Perhaps you can see an association between them that I can't see?
'wild rage on the road' is the wordplay.
'wild' indicates anagramming the letters.
'on' means one lot of letters go next to another.
'the road' becomes 'rd' (abbreviation for road).
'rage' anagrammed gives 'gera'.
'gera'+'rd'='GERARD'
Can you help me to learn more?
(Other definitions for gerard that I've seen before include "Baron Francois ______, Napoleonic court painter" , "Chap" , "Man" , "Man's name" .)