Disclose organisation to evil agitator (6)
I believe the answer is:
unveil
'disclose' is the definition.
(thesaurus)
'organisation to evil agitator' is the wordplay.
'organisation' becomes 'un' (UN is an example**).
'agitator' indicates anagramming the letters.
'evil' is an anagram of 'veil'.
'un'+'veil'='UNVEIL'
(Other definitions for unveil that I've seen before include "Remove covering, expose" , "Uncover, disclose" , "bare" , "Reveal by removing a curtain" , "Show or announce publicly for the first time" .)