Hungarian publication unknown artist set up (6)
I believe the answer is:
magyar
'hungarian' is the definition.
('Magyar' can be a synonym of 'hungarian')
'publication unknown artist set up' is the wordplay.
'publication' becomes 'mag' (abbreviation for magazine).
'unknown' becomes 'y' (algebra).
'artist' becomes 'ra' (Royal Academician, member of Royal Academy of Arts).
'set up' shows that the letters should be reversed in order.
'ra' back-to-front is 'ar'.
'mag'+'y'+'ar'='MAGYAR'
(Other definitions for magyar that I've seen before include "European" , "Hungarian language" , "Official language of Hungary" .)