1) Dune 
A barchan or barkhan dune, also known as a transverse dune, word origin Russian (bär-ˈkän, -ˈḵän), from Turkistan, credited as introduced in 1881 by Russian naturalist Alexander von Middendorf, for crescent-shaped sand dunes in Turkistan and other inland desert regions. Barchans face the wind, appearing convex and are produced by wind actio...
crescent-shaped sand dune produced by the action of wind predominately from one direction. One of the commonest types of dunes, it occurs in sandy ... [4 related articles]
A sand dune that is crescent-shaped in map view. Barchan dunes form in areas of limited sand supply.
A crescent-shaped sand dune moving across a clean surface with its convex face upwind and its concave slip face downwind.
A crescent-shaped sand dune with horns pointing downwind.