Falls once more returning with artist (7)
I believe the answer is:
niagara
'falls' is the definition.
(thesaurus)
'once more returning with artist' is the wordplay.
'once more' becomes 'again' ('again' can be a synonym of 'once more').
'returning' is a reversal indicator.
'with' means one lot of letters go next to another.
'artist' becomes 'ra' (Royal Academician, member of Royal Academy of Arts).
'again' back-to-front is 'niaga'.
'niaga'+'ra'='NIAGARA'
(Other definitions for niagara that I've seen before include "Great waterfalls on Canadian-US border" , "Famous waterfall" , "N. American waterfall" , "Great waterfalls on border of USA and Canada" , "North American waterfall" .)