Deal framing upstanding copper is malign (7)
I believe the answer is:
traduce
'malign' is the definition.
(synonyms)
'deal framing upstanding copper' is the wordplay.
'deal' becomes 'trade' (synonyms).
'framing' is an insertion indicator (inserted letters are framed by the outside letters).
'upstanding' is a reversal indicator.
'copper' becomes 'cu' (chemical symbol).
'cu' reversed gives 'uc'.
'trade' enclosing 'uc' is 'TRADUCE'.
'is' acts as a link.
(Other definitions for traduce that I've seen before include "'Malign, badmouth (7)'" , "Asperse" , "Slander - misrepresent" , "Malign -- rude act (anag)" , "Defame, slander" .)