Brazen editor goes after United Nations with a hoax (9)
I believe the answer is:
unashamed
'brazen' is the definition.
('unashamed' can be similar in meaning to 'brazen')
'editor goes after united nations with a hoax' is the wordplay.
'editor' becomes 'ed'.
'goes after' says to put letters next to each other.
'united nations' becomes 'un' ('UN' can be a synonym of 'united nations').
'with' says to put letters next to each other.
'hoax' becomes 'sham'.
'un'+'a'+'sham'='unasham'
'ed' after 'unasham' is 'UNASHAMED'.
(Other definitions for unashamed that I've seen before include "Showing no embarrassment" , "Not at all abashed or penitent" , "Not embarrassed" , "Impenitent" , "not apologetic" .)