What is "brychon"

Brychon or Vrychonas ( Ancient Greek: Βρύχων, Modern Greek: Βρύχωνας, English translation: "the roaring one") was the name of two different small rivers in Greece. One of them flows from Mount Pelion in Magnesia, Thessaly into the Pagasetic Gulf. It has been attested under that name since antiquity, and is today known as the location of Greece's oldest bridge made of fortified concrete, constructed for a train line in 1895. The other is said by ancient sources to have been in the Sithonia peninsula in Chalcidice, Macedonia (Greece), near Pallini. According to ancient mythology, the river god of the same name was an ally of the Gigantes in their war against the gods, the Gigantomachy, which according to some sources took place at Pallene.