The name Malthace is of Greek origin and means "Unknown." The origin is the culture in which the name originated, or in the case of a word--the language in which it most appears.
Malthace was a wife of King Herod the Great, the Roman-appointed king of Judea (37–4 BCE). She was the mother of Archelaus and Antipas. Character in the 1963 novel The Bronze Bow by Elizabeth George Spear. Nicknames for the name Malthace include Mal, Thace, and Thacia.