Bordeaux perhaps harbours English vessel (4)
I believe the answer is:
vein
'vessel' is the definition.
(vein is a kind of vessel)
'bordeaux perhaps harbours english' is the wordplay.
'bordeaux perhaps' becomes 'vin' (I can't justify this - if you can you should believe this answer much more).
'harbours' is an insertion indicator.
'english' becomes 'e' (abbreviation).
'vin' going around 'e' is 'VEIN'.
Can you help me to learn more?
(Other definitions for vein that I've seen before include "Distinctive quality" , "Tube that carries blood to the heart" , "Part of the blood circulation system" , "Leaf rib; ore layer in rock" , "Deposit of mineral" .)