Dune and Sand dune

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

Sand dune is a synonym for dune in hill topic. In some cases you can use "Sand dune" instead a noun "Dune". popular alternative

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

Dune is a synonym for sand dune. You can use "Dune" instead a noun phrase "Sand dune".