Road raised above water (8)
I believe the answer is:
causeway
'road raised above water' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for causeway that I've seen before include "Raised road or track" , "Raised path over water" , "Raised road across wet area" , "Raised road crossing shallow water" , "Raised road across water - may be a Giant's" .)