Astute form of memorial (6)
I believe the answer is:
statue
'memorial' is the definition.
(thesaurus)
'astute form' is the wordplay.
'form' indicates anagramming the letters.
'astute' anagrammed gives 'STATUE'.
'of' acts as a link.
(Other definitions for statue that I've seen before include "Sculptured figure" , "Piece of sculpture" , "Artistic figure" , "See figure" , "Model figure" .)