Skill shown by copper getting in the last word (6)
I believe the answer is:
acumen
'skill' is the definition.
The definition and answer can be both related to thinking as well as being singular nouns.
Perhaps there's an association between them I don't understand?
'copper getting in the last word' is the wordplay.
'copper' becomes 'Cu' (chemical symbol).
'getting in' means one lot of letters goes inside another.
'the last word' becomes 'amen' (last word in a prayer).
'cu' placed within 'amen' is 'ACUMEN'.
'shown by' acts as a link.
Can you help me to learn more?
(Other definitions for acumen that I've seen before include "show perception" , "Gumption" , "Penetrating insight" , "Wit" , "The ability to make good and quick decisions" .)