Norwegian inlets of the sea (6)
I believe the answer is:
fjords
'norwegian inlets of the sea' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for fjords that I've seen before include "More than one Channel" , "Scandinavian inlets" , "Rock-bound inlets" , "rocky inlets" , "Long narrow sea inlets between steep cliffs in Norway" .)