Answer: zuiderzee

AnswerCrossword Clue
ZUIDERZEELiterally, Dutch for "southern sea"
ZUIDERZEEThe IJsselmeer was part of it before construction of the Afsluitdijk
ZUIDERZEEBody of water, now Ijssel Lake.
ZUIDERZEEFeature of N and central Netherlands.
ZUIDERZEEOne-time inlet of the North Sea
ZUIDERZEEOnetime inlet of the North Sea