Start to drive gold Beetle (3)
I believe the answer is:
dor
'beetle' is the definition.
(I've seen this in another clue)
'start to drive gold' is the wordplay.
'start to' indicates taking the first letters.
'gold' becomes 'or' ('or' is the heraldic name for gold).
The first letter of 'drive' is 'd'.
'd'+'or'='DOR'
(Other definitions for dor that I've seen before include "European dung - beetle" , "Creature" , "Dung-beetle" .)