Men at work on gold cloak (7)
I believe the answer is:
manteau
'cloak' is the definition.
(I've seen this before)
'men at work on gold' is the wordplay.
'work' indicates an anagram.
'on' is a charade indicator (letters next to each other).
'gold' becomes 'Au' (Au is the chemical symbol for gold).
'men'+'at'='menat'
'menat' with letters rearranged gives 'mante'.
'mante'+'au'='MANTEAU'
(Other definitions for manteau that I've seen before include "Lady's loose gown" , "cloak" .)