Stop artist ascending with others (6)
I believe the answer is:
arrest
'stop' is the definition.
(I know that stop can be written as arrest)
'artist ascending with others' is the wordplay.
'artist' becomes 'RA' (Royal Academician, member of Royal Academy of Arts).
'ascending' says the letters should be written in reverse.
'with' means one lot of letters go next to another.
'others' becomes 'rest' (I've seen this in another clue).
'ra' back-to-front is 'ar'.
'ar'+'rest'='ARREST'
(Other definitions for arrest that I've seen before include "Nab" , "Stop (on suspicion)" , "Stop, check (progress)" , "Apprehend; detain" , "Seize (a crime suspect)" .)