Submissive medic on French island (6)
I believe the answer is:
docile
'submissive' is the definition.
(I've seen this before)
'medic on french island' is the wordplay.
'medic' becomes 'doc' (doctor).
'on' is a charade indicator (letters next to each other) (in a down clue, letters appear on others).
'french island' becomes 'ile' ('island' in French).
'doc'+'ile'='DOCILE'
(Other definitions for docile that I've seen before include "Gentle and pliant" , "Tractable and pliant" , "Easily handled or managed" , "asleep?" , "Tame, biddable" .)