Valued works disappear (9)
I believe the answer is:
appraised
'valued' is the definition.
('appraise' can be a synonym of 'value')
'works disappear' is the wordplay.
'works' is an anagram indicator.
'disappear' with letters rearranged gives 'APPRAISED'.
(Other definitions for appraised that I've seen before include "Disappear (anag)" , "Evaluated" , "Did judge" , "Valued" .)