- A mound or ridge of sand or other loose sediment formed by the wind, especially on the sea coast or in a desert: a sand duneMore example sentences
- Nothing but vast sand dunes and arid desert far as the eye could see in all directions.
- It is generally agreed that the linear dunes in the Namib Sand Sea have extended from south to north.
- The group will face eight days of walking across rocky plateaus, sand dunes and salt pans.
late 18th century: from French, from Middle Dutch dūne; related to Old English dūn 'hill' (see down3).