Caretaker sent back copper and silver vessels (7)
I believe the answer is:
stopgap
'caretaker' is the definition.
(I've seen this before)
'sent back copper and silver vessels' is the wordplay.
'sent back' shows that the letters should be reversed in order.
'copper' becomes 'p'.
'and' is a charade indicator (letters next to each other).
'silver' becomes 'Ag' (Ag is the chemical symbol for silver).
'vessels' becomes 'pots' (pot is a kind of vessel).
'p'+'ag'+'pots'='pagpots'
'pagpots' backwards is 'STOPGAP'.
(Other definitions for stopgap that I've seen before include "A temporary or impromptu substitute" , "Interim" , "Temporary fix" , "caretaker" , "Improvisation" .)