1. an area of low-lying land that has been reclaimed from the sea or a lake and is protected by dikes

Examples

• The Netherlands is famous for its polders, which make up much of the country’s farmland.
• Engineers built dikes around the polder to keep the water out.
• The new polder provided fertile soil for growing crops.
• Windmills were used to pump water from the polder back into the sea.
• The polder project took several years to complete.
• Farmers planted tulips in the rich soil of the polder.