Mud and Polder

Mud noun - Water soaked soil; soft wet earth.

Polder and mud are semantically related In some cases you can use "Polder" instead a noun "Mud".

Polder noun - Low-lying land that has been reclaimed and is protected by dikes (especially in the Netherlands).

Mud and polder are semantically related in swamp topic. You can use "Mud" instead a noun "Polder", if it concerns topics such as wet land covered with vegetation.