Clear where the US put copper until late last year, reportedly (8)
I believe the answer is:
innocent
'clear' is the definition.
(similar in meaning)
I don't understand how the rest of the clue works.
Can you help me to learn more?
(Other definitions for innocent that I've seen before include "Free from evil or guilt" , "Virgin" , "Naive, pure" , "Without blame or without guile" , "Simple and ignorant of evil" .)