/ djuːn; NAmE duːn/ (also ˈsand dune ) noun
a small hill of sand formed by the wind, near the sea or in a desert
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WORD ORIGIN
late 18th cent.: from French , from Middle Dutch dūne ; related to Old English dūn hill (related to Dutch duin dune), perhaps ultimately of Celtic origin and related to Old Irish dún and obsolete Welsh din fort.