Energy supplier to trace out gold (7)
I believe the answer is:
reactor
'energy supplier' is the definition.
Although both the answer and definition are singular nouns, I can't see how they can define each other.
'trace out gold' is the wordplay.
'out' indicates anagramming the letters (out can mean wrong or inaccurate).
'gold' becomes 'or' ('or' is the heraldic name for gold).
'trace' with letters rearranged gives 'react'.
'react'+'or'='REACTOR'
'to' is the link.
Can you help me to learn more?
(Other definitions for reactor that I've seen before include "Apparatus for production of nuclear energy" , "power supplier" , "Creator (anag.)" , "Nuclear power generator" , "nuclear facility" .)