In Greek it is spelled Μαριάμη (Mariame) by Josephus; in some editions of his work the second m is doubled (Mariamme).
In later copies of those editions the spelling was dissimilated to its now most common form, Mariamne.
In Hebrew, Mariamne is known as מִרְיָם, (Miriam), as in the Biblical name (see Miriam, the sister of Moses and Aaron); Mariamne is the Hellenized version of the Hebrew, as Koine Greek was a common language in the late Hasmonean era in Judea (together with Aramaic), where both Mariamnes lived.
For Gnostic readers Mariamne is also recognized as possibly being Mary Magdalene.
François Bovon, professor of the history of religion at Harvard University, has theorized based on his study of the Acts of Philip (which describes the apostle Philip as the brother of "Mariamne" or "Mariamme") that Mariamene, or Mariamne, was the actual name of Mary Magdalene.