From a merger of Old High German māno, from Proto-Germanic *mēnô, and Old High German mānōd, from Proto-Germanic *mēnōþs, both ultimately from Proto-Indo-European *mḗh₁n̥s. The two words were merged throughout Central Franconian (compare Mond (“moon; month”)). The distinction between Mound and Mount in current Luxembourgish spelling mirrors German Mond versus Monat. The plural Mounden is a neologism also based on German.
Mound m (plural Mounden)