Louisiana wetland (5)
I believe the answer is:
bayou
'louisiana wetland' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for bayou that I've seen before include "US marshland" , "Watery area (US)" , "marshy water in New Orleans?" , "AB, you could be in a marshy Louisiana inlet" , "Swampy area" .)