Caribbean island nation south of Martinique (2,5)
I believe the answer is:
st lucia
'caribbean island nation south of martinique' is the definition.
(I've seen this in another clue)
This is the entire clue.
(Other definitions for st lucia that I've seen before include "'Volcanic island in the Windward Isles (2,5)'" , "Commonwealth country in the Windward Islands" , "Windward Isles country to the south of Martinique" , "Caribbean country" .)