Stop artist turning up with others (6)
I believe the answer is:
arrest
'stop' is the definition.
(synonyms)
'artist turning up with others' is the wordplay.
'artist' becomes 'RA' (Royal Academician, member of Royal Academy of Arts).
'turning up' says the letters should be written in reverse.
'with' is a charade indicator (letters next to each other).
'others' becomes 'rest' (I've seen this in another clue).
'ra' written backwards gives 'ar'.
'ar'+'rest'='ARREST'
(Other definitions for arrest that I've seen before include "Bring to a standstill" , "apprehend a law-breaker" , "Sartre (anag) -- check" , "Seize (a crime suspect)" , "Stop or slow down the progress of" .)