Eurypylus was a name borne by several men, including a son of Poseidon who was a king in Libya, a son of Telephus who was a king of Pergamum, a former suitor of Helen from Thessaly, and another son of Poseidon who was another king (on the island of Cos).

With such a wealth of lordly personages we must expect a rather grand meaning for the name, and it is in fact 'wide gates', from eurys, 'wide' and pyle, 'gate'. 'He of the wide gate' is obviously a suitable name for the king of a city.