Very drunk on the French steamship (7)
I believe the answer is:
legless
'very drunk' is the definition.
(I've seen this before)
'on the french steamship' is the wordplay.
'on' becomes 'leg' (cricket term).
'the french' becomes 'le' ('the' in French).
'steamship' becomes 'ss' (nautical abbreviation).
'leg'+'le'+'ss'='LEGLESS'
(Other definitions for legless that I've seen before include "like a fish?" , "under the table" , "Drunk (as a worm?)" , "Mermaid is so" , "Showing result of drinking" .)