Dog leads of copper or richly gilded iron (5)
I believe the answer is:
corgi
'dog' is the definition.
(I know that corgi is a type of dog)
'leads of copper or richly gilded iron' is the wordplay.
'leads of' suggests taking the first letters (I've seen 'leading' mean this).
The first letters of 'copper or richly gilded iron' is 'CORGI'.
(Other definitions for corgi that I've seen before include "One of the Queen's dogs?" , "Cardigan, possibly" , "Little dog" , "HM's favourite dog" , "The Queen's favourite?" .)