City bard trained gold dog (8)
I believe the answer is:
labrador
'dog' is the definition.
(I know that labrador is a type of dog)
'city bard trained gold' is the wordplay.
'city' becomes 'LA' (Los Angeles).
'trained' indicates an anagram (train can mean to shape or manipulate).
'gold' becomes 'or' ('or' is the heraldic name for gold).
'bard' is an anagram of 'brad'.
'la'+'brad'+'or'='LABRADOR'
(Other definitions for labrador that I've seen before include "Coastal region of eastern Canada" , "Part of Newfoundland" , "Spaniard who works" , "Part of Canada; dog" , "Region of NE Canada, or a retriever dog" .)