Golden Fleece ship (4)
I believe the answer is:
argo
'golden fleece ship' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for argo that I've seen before include "Name of ship sailed by Jason in search of the Golden Fleece" , "Ship involved in the quest for the Golden Fleece" , "Ancient ship" , "Old boat" , "ancient boat" .)