Piled so could plunder (7)
I believe the answer is:
despoil
'plunder' is the definition.
(I know that plunder can be written as despoil)
'piled so' is the wordplay.
'piled so' anagrams to 'DESPOIL'.
However, I'm not sure how this is indicated.
'could' is the link.
Can you help me to learn more?
(Other definitions for despoil that I've seen before include "Plunder - piled so (anag)" , "Ravage" , "Plunder completely" , "Plunder, rob" , "Plunder (a place)" .)