What is "abdaraxus"

Abdaraxus was an ancient engineer mentioned in Vitruvius' De Architectura as the one "who built the machines in Alexandria". This is the only known mention of his name in surviving literature, but to include him in his list of twelve luminaries, alongside Archimedes and Philo, and to consider the machines famous enough to not need elaboration it can be inferred that Abdaraxus must have been an outstanding engineer of his time.