Latinized form of the given name Ἐτέανδρος (Eteandros)
. This was the name of a king of the city-kingdom of Paphos (located on the Greek island of Cyprus), who lived in the early 7th century BC. Like other Cypriot rulers of his time, he was a client king of the Neo-Assyrian Empire, seeing as the island had come under Assyrian rule during the late 8th century BC. But before the Assyrians had taken control of Cyprus, the island had been ruled by the Phoenician kingdom of Tyre since the 9th century BC.
Because of this, it is uncertain whether king Eteander was fully of Greek descent, or whether he was of Assyrian or Phoenician descent. As such, it is possible that his name is not an authentic Greek name, but actually the hellenized form of a Semitic name (as Assyrians and Phoenicians both spoke a Semitic language). He is called Ituandar
(also found spelled as Ithuander and Ituander) in Assyrian sources, so if he was indeed of Assyrian descent, then that is what his original name was. It is unknown what his original name would have been if he was of Phoenician descent, although it probably can't have been all that much different from the Assyrian form. Either way, in both cases, the meaning of his name is unknown.
Finally, if king Eteander was fully of Greek descent after all, then his name is most likely derived from Greek ἐτεός (eteos)
"true, genuine, real" combined with Greek ανδρος (andros)
"of a man". As such, the meaning of the name would basically be "a true man".