One outstanding among the best artists (4)
I believe the answer is:
star
'one outstanding' is the definition.
(thesaurus)
'among the best artists' is the wordplay.
'among' says the answer is hidden in the clue.
'STAR' is hidden in the letters of 'best artists'.
(Other definitions for star that I've seen before include "Heavenly body - leading actress?" , "Major" , "Luminary" , "Distant sun" , "Pointed symbol" .)