Hill that is made of Canadian copper (7)
I believe the answer is:
mountie
'canadian copper' is the definition.
The answer and definition can be both people as well as being singular nouns.
Perhaps you can see an association between them that I don't see?
'hill that is' is the wordplay.
'hill' becomes 'mount' (I've seen this before).
'that is' becomes 'ie' (short for Latin 'id est', 'that is').
'mount'+'ie'='MOUNTIE'
'made of' is the link.
Can you help me to learn more?
(Other definitions for mountie that I've seen before include "Canadian police officer" , "Canadian lawman" , "Horse-riding Canadian cop" , "Canadian policeman" , "Canadian policemen" .)