Acacus (Ἄκακος), in Greek mythology, was a king of Acacesium (Ἀκακήσιον) in Arcadia, the son of Lycaon, and the foster-father of the infant Hermes.
Maia gave birth to Hermes at dawn in a sacred cave on Mount Cyllene in Arcadia, and he was raised by Acacus. He was believed to be the founder of the Arcadian town of Acacesium where he was king.
References
Acacus (Greek mythology) Wikipedia(Text) CC BY-SA