Inferior, the French steamship (4)
I believe the answer is:
less
'inferior' is the definition.
('less' can be similar in meaning to 'inferior')
'the french steamship' is the wordplay.
'the french' becomes 'le' (**).
'steamship' becomes 'ss'.
'le'+'ss'='LESS'
(Other definitions for less that I've seen before include "Fewer; minus" , "inferior" , "minor" , "Smaller in amout or degree" , "A smaller amount" .)