Base of French vessel (5)
I believe the answer is:
depot
'base' is the definition.
(I've seen this before)
'of french vessel' is the wordplay.
'of french' becomes 'de' ('of' in French).
'vessel' becomes 'pot' (type of container).
'de'+'pot'='DEPOT'
(Other definitions for depot that I've seen before include "Toped (anag.)" , "Bus station in the US" , "(Military) store" , "Wherein bus drivers" , "Large storage site" .)