Last documents to be shredded after copper's gone (7)
I believe the answer is:
endmost
'last' is the definition.
(similar in meaning)
'documents to be shredded after copper's gone' is the wordplay.
I cannot quite see how this works, but
'be' could be 'end' (ending is a kind of being) and 'end' is found within the answer.
The remaining letters 'most' is a valid word which might be clued in a way I don't see.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for endmost that I've seen before include "Last in the line" , "Last in a row" , "final" , "Most distant" , "Farthest" .)