| 1 | Old Norse | mara | nightmare, incubus; to be waterlogged, float low... |
| 2 | Proto-Germanic | marǭ | evil spirit; succubus; incubus; nightmare |
| 3 | Proto-Indo-European | mor- | to blacken, to dirty; dirt spot; to rub, pound,... |
| 4 | Proto-Indo-European | mer- | to die; to disappear; sea, lake, wetland |