Unmasked, is brazen (9)
I believe the answer is:
barefaced
'is brazen' is the definition.
(synonyms)
I don't understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for barefaced that I've seen before include "Shameless or not bearded" , "Audacious" , "Shameless like liar, having shaven visage" , "such lies?" , "Unshaven kind of blatant liar" .)