In retrospect, some artists always endure (4)
I believe the answer is:
last
'endure' is the definition.
(synonyms)
'in retrospect some artists always' is the wordplay.
'in retrospect' says the letters should be written in reverse (in retrospect means looking back).
'some' indicates a hidden word (some parts of the word are used).
'tsal' is hidden within 'artists always'.
'tsal' in reverse letter order is 'LAST'.
(Other definitions for last that I've seen before include "part of Oxford's restoration with this?" , "Final; keep going" , "Shoemaker's shape" , "End" , "Endure - this clue is!" .)