French port at the head of the Loire estuary that was the scene of the Noyades during the French Revolution (6)
I believe the answer is:
nantes
(Other definitions for nantes that I've seen before include "City and port of W. France on the Loire" , "Western French port" , "French Atlantic port" , "French FC" , "City on the Loire, associated with 1598 edict ending the French Wars of Religion" .)