0 an area of low land that was once under the sea but that has been separated from it by dykes (= walls or channels built to prevent water covering an area):
A polder is a large area of land containing farms and villages encircled by dykes.
The polder system could isolate the flooding to a smaller area.
Following the damming, large areas of land were reclaimed in the newly freshwater lake body by means of polders.
The coastal plain consists mainly of sand dunes and polders.
After a few centuries, an additional way to keep the polders dry was required.
Kennemerland was a duneland, where the farmers had far fewer rights than the farmers in the polders.
Amphirols are used for ground surveying, for grooving the surface of newly drained polders to assist drying, and to carry soil-drilling teams.
