Unusually astute piece of work by an artist (6)
I believe the answer is:
statue
'piece of work by an artist' is the definition.
'unusually astute' is the wordplay.
'unusually' indicates an anagram.
'astute' anagrammed gives 'STATUE'.
(Other definitions for statue that I've seen before include "Sculpture of person or animal" , "Three-D human representation" , "Sculptured likeness" , "Eg, the Venus de Milo" , "Sculptured person" .)