Sandbank and Sand dune

Sandbank noun - A submerged bank of sand near a shore or in a river; can be exposed at low tide.

Sand dune and sandbank are semantically related. In some cases you can use "Sand dune" instead a noun "Sandbank".

Sand dune noun - A ridge of sand created by the wind; found in deserts or near lakes and oceans.

Sandbank and sand dune are semantically related. Sometimes you can use "Sandbank" instead a noun phrase "Sand dune".