Sailor finds the French competent (4)
I believe the answer is:
able
'competent' is the definition.
(similar in meaning)
'sailor finds the french' is the wordplay.
'sailor' becomes 'ab' (abbreviation for able seaman).
'finds' says to put letters next to each other.
'the french' becomes 'le' ('the' in French).
'ab'+'le'='ABLE'
(Other definitions for able that I've seen before include "... was I ere I saw Elba (palindrome)" , "Fitted" , "Bright" , "With the required capacities" , "Capable or proficient" .)