Shrink from any last corruption (7)
I believe the answer is:
analyst
'shrink' is the definition.
(shrink can informally mean a psychoanalyst)
'any last corruption' is the wordplay.
'corruption' indicates anagramming the letters.
'any'+'last'='anylast'
'anylast' with letters rearranged gives 'ANALYST'.
'from' acts as a link.
(Other definitions for analyst that I've seen before include "Dealer with systems - shrink!" , "One identifying (chemical) composition" , "Examiner - psychiatrist" , "Chemical researcher" , "Freud, perhaps" .)